Selecting a non-access stratum period based on a non-terrestrial access network type

ABSTRACT

A wireless device receives access network information indicating an access network type. Based on the access network type, a non-access stratum (NAS) period is selected among: a first value associated with a geostationary earth orbit (GEO) non-terrestrial network (NTN) access network type; and a second value associated with a low earth orbit (LEO) NTN access network type. A NAS procedure is initiated by sending a NAS request message. A start of the NAS period is based on the sending. The NAS procedure is aborted based on an expiry of the NAS period.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent Ser. No. 16/899,651,filed on Jun. 12, 2020, which claims the benefit of U.S. ProvisionalApplication No. 62/861,439, filed Jun. 14, 2019, which is herebyincorporated by reference in its entirety.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Examples of several of the various embodiments of the present inventionare described herein with reference to the drawings.

FIG. 1 is a diagram of an example 5G system architecture as per anaspect of an embodiment of the present disclosure.

FIG. 2 is a diagram of an example 5G System architecture as per anaspect of an embodiment of the present disclosure.

FIG. 3 is a system diagram of an example wireless device and a networknode in a 5G system as per an aspect of an embodiment of the presentdisclosure.

FIG. 4 is a system diagram of an example wireless device as per anaspect of an embodiment of the present disclosure.

FIG. 5A and FIG. 5B depict two registration management state models inUE 100 and AMF 155 as per an aspect of embodiments of the presentdisclosure.

FIG. 6A and FIG. 6B depict two connection management state models in UE100 and AMF 155 as per an aspect of embodiments of the presentdisclosure.

FIG. 7 is diagram for classification and marking traffic as per anaspect of an embodiment of the present disclosure.

FIG. 8 is an example call flow as per an aspect of an embodiment of thepresent disclosure.

FIG. 9 is an example call flow as per an aspect of an embodiment of thepresent disclosure.

FIG. 10 is an example call flow as per an aspect of an embodiment of thepresent disclosure.

FIG. 11 is an example call flow as per an aspect of an embodiment of thepresent disclosure.

FIG. 12 is an example call flow as per an aspect of an embodiment of thepresent disclosure.

FIG. 13 is an example call flow as per an aspect of an embodiment of thepresent disclosure.

FIG. 14 is an example architecture of a 5G system as per an aspect of anembodiment of the present disclosure.

FIG. 15A is an example non-terrestrial network architecture as an aspectof an embodiment of the present disclosure.

FIG. 15B is an example non-terrestrial network architecture as an aspectof an embodiment of the present disclosure.

FIG. 16 shows different types of non-terrestrial networks as an aspectof an embodiment of the present disclosure.

FIG. 17 depicts earth orbits of example satellites.

FIG. 18 is an example figure of different types of non-terrestrialnetwork platforms.

FIG. 19 shows examples of propagation delay corresponding to NTNs ofdifferent altitudes.

FIG. 20 is an example architecture of a 5G system having a 5G corenetwork that provides service to different types of access networks asper an aspect of an embodiment of the present disclosure.

FIG. 21 depicts an architecture (left side) and coverage map (rightside) of a deployment scenario in which one public land mobile network(e.g. PLMN A) provides both a non-terrestrial access network and aterrestrial access network as per an aspect of an embodiment of thepresent disclosure.

FIG. 22 depicts an architecture (left side) and coverage map (rightside) of a scenario in which two different public land mobile networks(e.g. PLMN A and PLMN B) respectively provide a non-terrestrial accessnetwork and a terrestrial access network.

FIG. 23 depicts an example control plane protocol stack between awireless device and various network functions as per an aspect of anembodiment of the present disclosure.

FIG. 24 illustrates a usage of an NAS timer in the context of aregistration procedure as per an aspect of an embodiment of the presentdisclosure.

FIG. 25 illustrates another usage of an NAS timer in the context of aregistration procedure as per an aspect of an embodiment of the presentdisclosure.

FIG. 26 illustrates an example embodiment of a present disclosure.

FIG. 27 illustrates an example embodiment of a present disclosure.

FIG. 28 illustrates an example embodiment of a present disclosure.

FIG. 29A illustrates an example embodiment of a present disclosure.

FIG. 29B illustrates an example embodiment of a present disclosure.

FIG. 30 illustrates an example flow chart of a present disclosure.

FIG. 31 illustrates an example flow chart of a present disclosure.

FIG. 32 is a flow diagram of an aspect of an example embodiment of thepresent disclosure.

FIG. 33 is a flow diagram of an aspect of an example embodiment of thepresent disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Example embodiments of the present invention enable implementation ofenhanced features and functionalities in 4G/5G systems. Embodiments ofthe technology disclosed herein may be employed in the technical fieldof 4G/5G systems and network slicing for communication systems. Moreparticularly, the embodiments of the technology disclosed herein mayrelate to 5G core network and 5G systems for network slicing incommunication systems. Throughout the present disclosure, UE, wirelessdevice, and mobile device are used interchangeably.

The following acronyms are used throughout the present disclosure:

5G 5th generation mobile networks

5GC 5G Core Network

5GS 5G System

5G-AN 5G Access Network

5QI 5G QoS Indicator

ACK Acknowledgement

AF Application Function

AMF Access and Mobility Management Function

AN Access Network

CDR Charging Data Record

CCNF Common Control Network Functions

CIoT Cellular IoT

CN Core Network

CP Control Plane

DDN Downlink Data Notification

DL Downlink

DN Data Network

DNN Data Network Name

DRX Discontinuous Reception

eNB Evolved Node B

F-TEID Fully Qualified TEID

gNB next generation Node B

GPSI Generic Public Subscription Identifier

GTP GPRS Tunneling Protocol

GUTI Globally Unique Temporary Identifier

HPLMN Home Public Land Mobile Network

IMSI International Mobile Subscriber Identity

LADN Local Area Data Network

LI Lawful Intercept

MEI Mobile Equipment Identifier

MICO Mobile Initiated Connection Only

MME Mobility Management Entity

MO Mobile Originated

MSISDN Mobile Subscriber ISDN

MT Mobile Terminating

N3IWF Non-3GPP InterWorking Function

NAI Network Access Identifier

NAS Non- Access Stratum

NB-IoT Narrow Band IoT

NEF Network Exposure Function

NF Network Function

NGAP Next Generation Application Protocol

ng-eNB Next Generation Evolved Node B

NG-RAN Next Generation Radio Access Network

NR New Radio

NRF Network Repository Function

NSI Network Slice Instance

NSSAI Network Slice Selection Assistance Information

NSSF Network Slice Selection Function

OCS Online Charging System

OFCS Offline Charging System

PCF Policy Control Function

PDU Packet/Protocol Data Unit

PEI Permanent Equipment Identifier

PLMN Public Land Mobile Network

PRACH Physical Random Access Channel

PLMN Public Land Mobile Network

RAN Radio Access Network

QFI QoS Flow Identity

RM Registration Management

S1-AP S1 Application Protocol

SBA Service Based Architecture

SEA Security Anchor Function

SCM Security Context Management

SI System Information

SIB System Information Block

SMF Session Management Function

SMSF SMS Function

S-NSSAI Single Network Slice Selection Assistance information

SUCI Served User Correlation ID

SUPI Subscriber Permanent Identifier

TEID Tunnel Endpoint Identifier

UE User Equipment

UL Uplink

UL CL Uplink Classifier

UPF User Plane Function

VPLMN Visited Public Land Mobile Network

Example FIG. 1 and FIG. 2 depict a 5G system comprising of accessnetworks and 5G core network. An example 5G access network may comprisean access network connecting to a 5G core network. An access network maycomprise an NG-RAN 105 and/or non-3GPP AN 165. An example 5G corenetwork may connect to one or more 5G access networks 5G-AN and/orNG-RANs. 5G core network may comprise functional elements or networkfunctions as in example FIG. 1 and example FIG. 2 where interfaces maybe employed for communication among the functional elements and/ornetwork elements.

In an example, a network function may be a processing function in anetwork, which may have a functional behavior and/or interfaces. Anetwork function may be implemented either as a network element on adedicated hardware, and/or a network node as depicted in FIG. 3 and FIG.4 , or as a software instance running on a dedicated hardware and/orshared hardware, or as a virtualized function instantiated on anappropriate platform.

In an example, access and mobility management function, AMF 155, mayinclude the following functionalities (some of the AMF 155functionalities may be supported in a single instance of an AMF 155):termination of RAN 105 CP interface (N2), termination of NAS (N1), NASciphering and integrity protection, registration management, connectionmanagement, reachability management, mobility management, lawfulintercept (for AMF 155 events and interface to LI system), providetransport for session management, SM messages between UE 100 and SMF160, transparent proxy for routing SM messages, access authentication,access authorization, provide transport for SMS messages between UE 100and SMSF, security anchor function, SEA, interaction with the AUSF 150and the UE 100, receiving the intermediate key established as a resultof the UE 100 authentication process, security context management, SCM,that receives a key from the SEA that it uses to derive access networkspecific keys, and/or the like.

In an example, the AMF 155 may support non-3GPP access networks throughN2 interface with N3IWF 170, NAS signaling with a UE 100 over N3IWF 170,authentication of UEs connected over N3IWF 170, management of mobility,authentication, and separate security context state(s) of a UE 100connected via non-3GPP access 165 or connected via 3GPP access 105 andnon-3GPP access 165 simultaneously, support of a coordinated RM contextvalid over 3GPP access 105 and non 3GPP access 165, support of CMmanagement contexts for the UE 100 for connectivity over non-3GPPaccess, and/or the like.

In an example, an AMF 155 region may comprise one or multiple AMF 155sets. The AMF 155 set may comprise some AMF 155 that serve a given areaand/or network slice(s). In an example, multiple AMF 155 sets may be perAMF 155 region and/or network slice(s). Application identifier may be anidentifier that may be mapped to a specific application trafficdetection rule. Configured NSSAI may be an NSSAI that may be provisionedin a UE 100. DN 115 access identifier (DNAI), for a DNN, may be anidentifier of a user plane access to a DN 115. Initial registration maybe related to a UE 100 registration in RM-DEREGISTERED 500, 520 states.N2AP UE 100 association may be a logical per UE 100 association betweena 5G AN node and an AMF 155. N2AP UE-TNLA-binding may be a bindingbetween a N2AP UE 100 association and a specific transport networklayer, TNL association for a given UE 100.

In an example, session management function, SMF 160, may include one ormore of the following functionalities (one or more of the SMF 160functionalities may be supported in a single instance of a SMF 160):session management (e.g. session establishment, modify and release,including tunnel maintain between UPF 110 and AN 105 node), UE 100 IPaddress allocation & management (including optional authorization),selection and control of UP function(s), configuration of trafficsteering at UPF 110 to route traffic to proper destination, terminationof interfaces towards policy control functions, control part of policyenforcement and QoS. lawful intercept (for SM events and interface to LISystem), termination of SM parts of NAS messages, downlink datanotification, initiation of AN specific SM information, sent via AMF 155over N2 to (R)AN 105, determination of SSC mode of a session, roamingfunctionality, handling local enforcement to apply QoS SLAs (VPLMN),charging data collection and charging interface (VPLMN), lawfulintercept (in VPLMN for SM events and interface to LI System), supportfor interaction with external DN 115 for transport of signaling for PDUsession authorization/authentication by external DN 115, and/or thelike.

In an example, a user plane function, UPF 110, may include one or moreof the following functionalities (some of the UPF 110 functionalitiesmay be supported in a single instance of a UPF 110): anchor point forIntra-/Inter-RAT mobility (when applicable), external PDU session pointof interconnect to DN 115, packet routing & forwarding, packetinspection and user plane part of policy rule enforcement, lawfulintercept (UP collection), traffic usage reporting, uplink classifier tosupport routing traffic flows to a data network, branching point tosupport multi-homed PDU session(s), QoS handling for user plane, uplinktraffic verification (SDF to QoS flow mapping), transport level packetmarking in the uplink and downlink, downlink packet buffering, downlinkdata notification triggering, and/or the like.

In an example, the UE 100 IP address management may include allocationand release of the UE 100 IP address and/or renewal of the allocated IPaddress. The UE 100 may set a requested PDU type during a PDU sessionestablishment procedure based on its IP stack capabilities and/orconfiguration. In an example, the SMF 160 may select PDU type of a PDUsession. In an example, if the SMF 160 receives a request with PDU typeset to IP, the SMF 160 may select PDU type IPv4 or IPv6 based on DNNconfiguration and/or operator policies. In an example, the SMF 160 mayprovide a cause value to the UE 100 to indicate whether the other IPversion is supported on the DNN. In an example, if the SMF 160 receivesa request for PDU type IPv4 or IPv6 and the requested IP version issupported by the DNN the SMF 160 may select the requested PDU type.

In an example embodiment, the 5GC elements and UE 100 may support thefollowing mechanisms: during a PDU session establishment procedure, theSMF 160 may send the IP address to the UE 100 via SM NAS signaling. TheIPv4 address allocation and/or IPv4 parameter configuration via DHCPv4may be employed once PDU session may be established. IPv6 prefixallocation may be supported via IPv6 stateless autoconfiguration, ifIPv6 is supported. In an example, 5GC network elements may support IPv6parameter configuration via stateless DHCPv6.

The 5GC may support the allocation of a static IPv4 address and/or astatic IPv6 prefix based on subscription information in a UDM 140 and/orbased on the configuration on a per-subscriber, per-DNN basis.

User plane function(s) (UPF 110) may handle the user plane path of PDUsessions. A UPF 110 that provides the interface to a data network maysupport functionality of a PDU session anchor.

In an example, a policy control function, PCF 135, may support unifiedpolicy framework to govern network behavior, provide policy rules tocontrol plane function(s) to enforce policy rules, implement a front endto access subscription information relevant for policy decisions in auser data repository (UDR), and/or the like.

A network exposure function, NEF 125, may provide means to securelyexpose the services and capabilities provided by the 3GPP networkfunctions, translate between information exchanged with the AF 145 andinformation exchanged with the internal network functions, receiveinformation from other network functions, and/or the like.

In an example, a network repository function, NRF 130 may supportservice discovery function that may receive NF discovery request from NFinstance, provide information about the discovered NF instances (bediscovered) to the NF instance, and maintain information about availableNF instances and their supported services, and/or the like.

In an example, an NSSF 120 may select a set of network slice instancesserving the UE 100, may determine allowed NSSAI. In an example, the NSSF120 may determine the AMF 155 set to be employed to serve the UE 100,and/or, based on configuration, determine a list of candidate AMF 155(s)155 by querying the NRF 130.

In an example, stored data in a UDR may include at least usersubscription data, including at least subscription identifiers, securitycredentials, access and mobility related subscription data, sessionrelated subscription data, policy data, and/or the like.

In an example, an AUSF 150 may support authentication server function(AUSF 150).

In an example, an application function (AF), AF 145, may interact withthe 3GPP core network to provide services. In an example, based onoperator deployment, application functions may be trusted by theoperator to interact directly with relevant network functions.Application functions not allowed by the operator to access directly thenetwork functions may use an external exposure framework (e.g., via theNEF 125) to interact with relevant network functions.

In an example, control plane interface between the (R)AN 105 and the 5Gcore may support connection of multiple different kinds of AN(s) (e.g.3GPP RAN 105, N3IWF 170 for Un-trusted access 165) to the 5GC via acontrol plane protocol. In an example, an N2 AP protocol may be employedfor both the 3GPP access 105 and non-3GPP access 165. In an example,control plane interface between the (R)AN 105 and the 5G core maysupport decoupling between AMF 155 and other functions such as SMF 160that may need to control the services supported by AN(s) (e.g. controlof the UP resources in the AN 105 for a PDU session).

In an example, the 5GC may provide policy information from the PCF 135to the UE 100. In an example, the policy information may comprise:access network discovery and selection policy, UE 100 route selectionpolicy (URSP), SSC mode selection policy (SSCMSP), network sliceselection policy (NSSP), DNN selection policy, non-seamless offloadpolicy, and/or the like.

In an example, as depicted in example FIG. 5A and FIG. 5B, theregistration management, RM may be employed to register or de-register aUE/user 100 with the network and establish the user context in thenetwork. Connection management may be employed to establish and releasethe signaling connection between the UE 100 and the AMF 155.

In an example, a UE 100 may register with the network to receiveservices that require registration. In an example, the UE 100 may updateits registration with the network periodically in order to remainreachable (periodic registration update), or upon mobility (e.g.,mobility registration update), or to update its capabilities or tore-negotiate protocol parameters.

In an example, an initial registration procedure as depicted in exampleFIG. 8 and FIG. 9 may involve execution of network access controlfunctions (e.g. user authentication and access authorization based onsubscription profiles in UDM 140). Example FIG. 9 is a continuation ofthe initial registration procedure depicted in FIG. 8 . As a result ofthe initial registration procedure, the identity of the serving AMF 155may be registered in a UDM 140.

In an example, the registration management, RM procedures may beapplicable over both 3GPP access 105 and non 3GPP access 165.

An example FIG. 5A may depict the RM states of a UE 100 as observed bythe UE 100 and AMF 155. In an example embodiment, two RM states may beemployed in the UE 100 and the AMF 155 that may reflect the registrationstatus of the UE 100 in the selected PLMN: RM-DEREGISTERED 500, andRM-REGISTERED 510. In an example, in the RM DEREGISTERED state 500, theUE 100 may not be registered with the network. The UE 100 context in theAMF 155 may not hold valid location or routing information for the UE100 so the UE 100 may not be reachable by the AMF 155. In an example,the UE 100 context may be stored in the UE 100 and the AMF 155. In anexample, in the RM REGISTERED state 510, the UE 100 may be registeredwith the network. In the RM-REGISTERED 510 state, the UE 100 may receiveservices that may require registration with the network.

In an example embodiment, two RM states may be employed in AMF 155 forthe UE 100 that may reflect the registration status of the UE 100 in theselected PLMN: RM-DEREGISTERED 520, and RM-REGISTERED 530.

As depicted in example FIG. 6A and FIG. 6B, connection management, CM,may comprise establishing and releasing a signaling connection between aUE 100 and an AMF 155 over N1 interface. The signaling connection may beemployed to enable NAS signaling exchange between the UE 100 and thecore network. The signaling connection between the UE 100 and the AMF155 may comprise both the AN signaling connection between the UE 100 andthe (R)AN 105 (e.g. RRC connection over 3GPP access) and the N2connection for the UE 100 between the AN and the AMF 155.

As depicted in example FIG. 6A and FIG. 6B, two CM states may beemployed for the NAS signaling connectivity of the UE 100 with the AMF155, CM-IDLE 600, 620 and CM-CONNECTED 610, 630. A UE 100 in CM-IDLE 600state may be in RM-REGISTERED 510 state and may have no NAS signalingconnection established with the AMF 155 over N1. The UE 100 may performcell selection, cell reselection, PLMN selection, and/or the like. A UE100 in CM-CONNECTED 610 state may have a NAS signaling connection withthe AMF 155 over N1.

In an example embodiment two CM states may be employed for the UE 100 atthe AMF 155, CM-IDLE 620 and CM-CONNECTED 630.

In an example, an RRC inactive state may apply to NG-RAN (e.g. it mayapply to NR and E-UTRA connected to 5G CN). The AMF 155, based onnetwork configuration, may provide assistance information to the NG RAN105, to assist the NG RAN's 105 decision whether the UE 100 may be sentto RRC inactive state. When a UE 100 is CM-CONNECTED 610 with RRCinactive state, the UE 100 may resume the RRC connection due to uplinkdata pending, mobile initiated signaling procedure, as a response to RAN105 paging, to notify the network that it has left the RAN 105notification area, and/or the like.

In an example, a NAS signaling connection management may includeestablishing and releasing a NAS signaling connection. A NAS signalingconnection establishment function may be provided by the UE 100 and theAMF 155 to establish the NAS signaling connection for the UE 100 inCM-IDLE 600 state. The procedure of releasing the NAS signalingconnection may be initiated by the 5G (R)AN 105 node or the AMF 155.

In an example, reachability management of a UE 100 may detect whetherthe UE 100 is reachable and may provide the UE 100 location (e.g. accessnode) to the network to reach the UE 100. Reachability management may bedone by paging the UE 100 and the UE 100 location tracking. The UE 100location tracking may include both UE 100 registration area tracking andUE 100 reachability tracking. The UE 100 and the AMF 155 may negotiateUE 100 reachability characteristics in CM-IDLE 600, 620 state duringregistration and registration update procedures.

In an example, two UE 100 reachability categories may be negotiatedbetween a UE 100 and an AMF 155 for CM-IDLE 600, 620 state. 1) UE 100reachability allowing mobile device terminated data while the UE 100 isCM-IDLE 600 mode. 2) Mobile initiated connection only (MICO) mode. The5GC may support a PDU connectivity service that provides exchange ofPDUs between the UE 100 and a data network identified by a DNN. The PDUconnectivity service may be supported via PDU sessions that areestablished upon request from the UE 100.

In an example, a PDU session may support one or more PDU session types.PDU sessions may be established (e.g. upon UE 100 request), modified(e.g. upon UE 100 and 5GC request) and/or released (e.g. upon UE 100 and5GC request) using NAS SM signaling exchanged over N1 between the UE 100and the SMF 160. Upon request from an application server, the 5GC may beable to trigger a specific application in the UE 100. When receiving thetrigger, the UE 100 may send it to the identified application in the UE100. The identified application in the UE 100 may establish a PDUsession to a specific DNN.

In an example, the 5G QoS model may support a QoS flow based frameworkas depicted in example FIG. 7 . The 5G QoS model may support both QoSflows that require a guaranteed flow bit rate and QoS flows that may notrequire a guaranteed flow bit rate. In an example, the 5G QoS model maysupport reflective QoS. The QoS model may comprise flow mapping orpacket marking at the UPF 110 (CN_UP) 110, AN 105 and/or the UE 100. Inan example, packets may arrive from and/or destined to theapplication/service layer 730 of UE 100, UPF 110 (CN_UP) 110, and/or theAF 145.

In an example, the QoS flow may be a granularity of QoS differentiationin a PDU session. A QoS flow ID, QFI, may be employed to identify theQoS flow in the 5G system. In an example, user plane traffic with thesame QFI within a PDU session may receive the same traffic forwardingtreatment. The QFI may be carried in an encapsulation header on N3and/or N9 (e.g. without any changes to the end-to-end packet header). Inan example, the QFI may be applied to PDUs with different types ofpayload. The QFI may be unique within a PDU session.

In an example, the QoS parameters of a QoS flow may be provided to the(R)AN 105 as a QoS profile over N2 at PDU session establishment, QoSflow establishment, or when NG-RAN is used at every time the user planeis activated. In an example, a default QoS rule may be required forevery PDU session. The SMF 160 may allocate the QFI for a QoS flow andmay derive QoS parameters from the information provided by the PCF 135.In an example, the SMF 160 may provide the QFI together with the QoSprofile containing the QoS parameters of a QoS flow to the (R)AN 105.

In an example, 5G QoS flow may be a granularity for QoS forwardingtreatment in the 5G system. Traffic mapped to the same 5G QoS flow mayreceive the same forwarding treatment (e.g. scheduling policy, queuemanagement policy, rate shaping policy, RLC configuration, and/or thelike). In an example, providing different QoS forwarding treatment mayrequire separate 5G QoS flows.

In an example, a 5G QoS indicator may be a scalar that may be employedas a reference to a specific QoS forwarding behavior (e.g. packet lossrate, packet delay budget) to be provided to a 5G QoS flow. In anexample, the 5G QoS indicator may be implemented in the access networkby the 5QI referencing node specific parameters that may control the QoSforwarding treatment (e.g. scheduling weights, admission thresholds,queue management thresholds, link layer protocol configuration, and/orthe like.).

In an example, 5GC may support edge computing and may enable operator(s)and 3rd party services to be hosted close to the UE's access point ofattachment. The 5G core network may select a UPF 110 close to the UE 100and may execute the traffic steering from the UPF 110 to the local datanetwork via a N6 interface. In an example, the selection and trafficsteering may be based on the UE's 100 subscription data, UE 100location, the information from application function AF 145, policy,other related traffic rules, and/or the like. In an example, the 5G corenetwork may expose network information and capabilities to an edgecomputing application function. The functionality support for edgecomputing may include local routing where the 5G core network may selecta UPF 110 to route the user traffic to the local data network, trafficsteering where the 5G core network may select the traffic to be routedto the applications in the local data network, session and servicecontinuity to enable UE 100 and application mobility, user planeselection and reselection, e.g. based on input from applicationfunction, network capability exposure where 5G core network andapplication function may provide information to each other via NEf 125,QoS and charging where PCF 135 may provide rules for QoS control andcharging for the traffic routed to the local data network, support oflocal area data network where 5G core network may provide support toconnect to the LADN in a certain area where the applications aredeployed, and/or the like.

An example 5G system may be a 3GPP system comprising of 5G accessnetwork 105, 5G core network and a UE 100, and/or the like. AllowedNSSAI may be an NSSAI provided by a serving PLMN during e.g. aregistration procedure, indicating the NSSAI allowed by the network forthe UE 100 in the serving PLMN for the current registration area.

In an example, a PDU connectivity service may provide exchange of PDUsbetween a UE 100 and a data network. A PDU session may be an associationbetween the UE 100 and the data network, DN 115, that may provide thePDU connectivity service. The type of association may be IP, Ethernetand/or unstructured.

Establishment of user plane connectivity to a data network via networkslice instance(s) may comprise the following: performing a RM procedureto select an AMF 155 that supports the required network slices, andestablishing one or more PDU session(s) to the required data network viathe network slice instance(s).

In an example, the set of network slices for a UE 100 may be changed atany time while the UE 100 may be registered with the network, and may beinitiated by the network, or the UE 100.

In an example, a periodic registration update may be UE 100re-registration at expiry of a periodic registration timer. A requestedNSSAI may be a NSSAI that the UE 100 may provide to the network.

In an example, a service based interface may represent how a set ofservices may be provided/exposed by a given NF.

In an example, a service continuity may be an uninterrupted userexperience of a service, including the cases where the IP address and/oranchoring point may change. In an example, a session continuity mayrefer to continuity of a PDU session. For PDU session of IP type sessioncontinuity may imply that the IP address is preserved for the lifetimeof the PDU session. An uplink classifier may be a UPF 110 functionalitythat aims at diverting uplink traffic, based on filter rules provided bythe SMF 160, towards data network, DN 115.

In an example, the 5G system architecture may support data connectivityand services enabling deployments to use techniques such as e.g. networkfunction virtualization and/or software defined networking. The 5Gsystem architecture may leverage service-based interactions betweencontrol plane (CP) network functions where identified. In 5G systemarchitecture, separation of the user plane (UP) functions from thecontrol plane functions may be considered. A 5G system may enable anetwork function to interact with other NF(s) directly if required.

In an example, the 5G system may reduce dependencies between the accessnetwork (AN) and the core network (CN). The architecture may comprise aconverged access-agnostic core network with a common AN-CN interfacewhich may integrate different 3GPP and non-3GPP access types.

In an example, the 5G system may support a unified authenticationframework, stateless NFs, where the compute resource is decoupled fromthe storage resource, capability exposure, and concurrent access tolocal and centralized services. To support low latency services andaccess to local data networks, UP functions may be deployed close to theaccess network.

In an example, the 5G system may support roaming with home routedtraffic and/or local breakout traffic in the visited PLMN. An example 5Garchitecture may be service-based and the interaction between networkfunctions may be represented in two ways. (1) As service-basedrepresentation (depicted in example FIG. 1 ), where network functionswithin the control plane, may enable other authorized network functionsto access their services. This representation may also includepoint-to-point reference points where necessary. (2) Reference pointrepresentation, showing the interaction between the NF services in thenetwork functions described by point-to-point reference point (e.g. N11)between any two network functions.

In an example, a network slice may comprise the core network controlplane and user plane network functions, the 5G Radio Access Network; theN3IWF functions to the non-3GPP Access Network, and/or the like. Networkslices may differ for supported features and network functionimplementation. The operator may deploy multiple network slice instancesdelivering the same features but for different groups of UEs, e.g. asthey deliver a different committed service and/or because they may bededicated to a customer. The NSSF 120 may store the mapping informationbetween slice instance ID and NF ID (or NF address).

In an example, a UE 100 may simultaneously be served by one or morenetwork slice instances via a 5G-AN. In an example, the UE 100 may beserved by k network slices (e.g. k=8, 16, etc.) at a time. An AMF 155instance serving the UE 100 logically may belong to a network sliceinstance serving the UE 100.

In an example, a PDU session may belong to one specific network sliceinstance per PLMN. In an example, different network slice instances maynot share a PDU session. Different slices may have slice-specific PDUsessions using the same DNN.

An S-NSSAI (Single Network Slice Selection Assistance information) mayidentify a network slice. An S-NSSAI may comprise a slice/service type(SST), which may refer to the expected network slice behavior in termsof features and services; and/or a slice differentiator (SD). A slicedifferentiator may be optional information that may complement theslice/service type(s) to allow further differentiation for selecting anetwork slice instance from potentially multiple network slice instancesthat comply with the indicated slice/service type. In an example, thesame network slice instance may be selected employing differentS-NSSAIs. The CN part of a network slice instance(s) serving a UE 100may be selected by CN.

In an example, subscription data may include the S-NSSAI(s) of thenetwork slices that the UE 100 subscribes to. One or more S-NSSAIs maybe marked as default S-NSSAI. In an example, k S-NSSAI may be markeddefault S-NSSAI (e.g. k=8, 16, etc.). In an example, the UE 100 maysubscribe to more than 8 S-NSSAIs.

In an example, a UE 100 may be configured by the HPLMN with a configuredNSSAI per PLMN. Upon successful completion of a UE's registrationprocedure, the UE 100 may obtain from the AMF 155 an Allowed NSSAI forthis PLMN, which may include one or more S-NSSAIs.

In an example, the Allowed NSSAI may take precedence over the configuredNSSAI for a PLMN. The UE 100 may use the S-NSSAIs in the allowed NSSAIcorresponding to a network slice for the subsequent network sliceselection related procedures in the serving PLMN.

In an example, the establishment of user plane connectivity to a datanetwork via a network slice instance(s) may comprise: performing a RMprocedure to select an AMF 155 that may support the required networkslices, establishing one or more PDU sessions to the required datanetwork via the network slice instance(s), and/or the like.

In an example, when a UE 100 registers with a PLMN, if the UE 100 forthe PLMN has a configured NSSAI or an allowed NSSAI, the UE 100 mayprovide to the network in RRC and NAS layer a requested NSSAI comprisingthe S-NSSAI(s) corresponding to the slice(s) to which the UE 100attempts to register, a temporary user ID if one was assigned to the UE,and/or the like. The requested NSSAI may be configured-NSSAI,allowed-NSSAI, and/or the like.

In an example, when a UE 100 registers with a PLMN, if for the PLMN theUE 100 has no configured NSSAI or allowed NSSAI, the RAN 105 may routeNAS signaling from/to the UE 100 to/from a default AMF 155.

In an example, the network, based on local policies, subscriptionchanges and/or UE 100 mobility, may change the set of permitted networkslice(s) to which the UE 100 is registered. In an example, the networkmay perform the change during a registration procedure or trigger anotification towards the UE 100 of the change of the supported networkslices using an RM procedure (which may trigger a registrationprocedure). The network may provide the UE 100 with a new allowed NSSAIand tracking area list.

In an example, during a registration procedure in a PLMN, in case thenetwork decides that the UE 100 should be served by a different AMF 155based on network slice(s) aspects, the AMF 155 that first received theregistration request may redirect the registration request to anotherAMF 155 via the RAN 105 or via direct signaling between the initial AMF155 and the target AMF 155.

In an example, the network operator may provision the UE 100 withnetwork slice selection policy (NSSP). The NSSP may comprise one or moreNSSP rules.

In an example, if a UE 100 has one or more PDU sessions establishedcorresponding to a specific S-NSSAI, the UE 100 may route the user dataof the application in one of the PDU sessions, unless other conditionsin the UE 100 may prohibit the use of the PDU sessions. If theapplication provides a DNN, then the UE 100 may consider the DNN todetermine which PDU session to use. In an example, if the UE 100 doesnot have a PDU session established with the specific S-NSSAI, the UE 100may request a new PDU session corresponding to the S-NSSAI and with theDNN that may be provided by the application. In an example, in order forthe RAN 105 to select a proper resource for supporting network slicingin the RAN 105, the RAN 105 may be aware of the network slices used bythe UE 100.

In an example, an AMF 155 may select an SMF 160 in a network sliceinstance based on S-NSSAI, DNN and/or other information e.g. UE 100subscription and local operator policies, and/or the like, when the UE100 triggers the establishment of a PDU session. The selected SMF 160may establish the PDU session based on S-NSSAI and DNN.

In an example, in order to support network-controlled privacy of sliceinformation for the slices the UE 100 may access, when the UE 100 isaware or configured that privacy considerations may apply to NSSAI, theUE 100 may not include NSSAI in NAS signaling unless the UE 100 has aNAS security context and the UE 100 may not include NSSAI in unprotectedRRC signaling.

In an example, for roaming scenarios, the network slice specific networkfunctions in VPLMN and HPLMN may be selected based on the S-NSSAIprovided by the UE 100 during PDU connection establishment. If astandardized S-NSSAI is used, selection of slice specific NF instancesmay be done by each PLMN based on the provided S-NSSAI. In an example,the VPLMN may map the S-NSSAI of HPLMN to a S-NSSAI of VPLMN based onroaming agreement (e.g., including mapping to a default S-NSSAI ofVPLMN). In an example, the selection of slice specific NF instance inVPLMN may be done based on the S-NSSAI of VPLMN. In an example, theselection of any slice specific NF instance in HPLMN may be based on theS-NSSAI of HPLMN.

As depicted in example FIG. 8 and FIG. 9 , a registration procedure maybe performed by the UE 100 to get authorized to receive services, toenable mobility tracking, to enable reachability, and/or the like.

In an example, the UE 100 may send to the (R)AN 105 an AN message 805(comprising AN parameters, RM-NAS registration request (registrationtype, SUCI or SUPI or 5G-GUTI, last visited TAI (if available), securityparameters, requested NSSAI, mapping of requested NSSAI, UE 100 5GCcapability, PDU session status, PDU session(s) to be re-activated,Follow on request, MICO mode preference, and/or the like), and/or thelike). In an example, in case of NG-RAN, the AN parameters may includee.g. SUCI or SUPI or the 5G-GUTI, the Selected PLMN ID and requestedNSSAI, and/or the like. In an example, the AN parameters may compriseestablishment cause. The establishment cause may provide the reason forrequesting the establishment of an RRC connection. In an example, theregistration type may indicate if the UE 100 wants to perform an initialregistration (e.g. the UE 100 is in RM-DEREGISTERED state), a mobilityregistration update (e.g., the UE 100 is in RM-REGISTERED state andinitiates a registration procedure due to mobility), a periodicregistration update (e.g., the UE 100 is in RM-REGISTERED state and mayinitiate a registration procedure due to the periodic registrationupdate timer expiry) or an emergency registration (e.g., the UE 100 isin limited service state). In an example, if the UE 100 performing aninitial registration (e.g., the UE 100 is in RM-DEREGISTERED state) to aPLMN for which the UE 100 does not already have a 5G-GUTI, the UE 100may include its SUCI or SUPI in the registration request. The SUCI maybe included if the home network has provisioned the public key toprotect SUPI in the UE. If the UE 100 received a UE 100 configurationupdate command indicating that the UE 100 needs to re-register and the5G-GUTI is invalid, the UE 100 may perform an initial registration andmay include the SUPI in the registration request message. For anemergency registration, the SUPI may be included if the UE 100 does nothave a valid 5G-GUTI available; the PEI may be included when the UE 100has no SUPI and no valid 5G-GUTI. In other cases, the 5G-GUTI may beincluded and it may indicate the last serving AMF 155. If the UE 100 isalready registered via a non-3GPP access in a PLMN different from thenew PLMN (e.g., not the registered PLMN or an equivalent PLMN of theregistered PLMN) of the 3GPP access, the UE 100 may not provide over the3GPP access the 5G-GUTI allocated by the AMF 155 during the registrationprocedure over the non-3GPP access. If the UE 100 is already registeredvia a 3GPP access in a PLMN (e.g., the registered PLMN), different fromthe new PLMN (e.g. not the registered PLMN or an equivalent PLMN of theregistered PLMN) of the non-3GPP access, the UE 100 may not provide overthe non-3GPP access the 5G-GUTI allocated by the AMF 155 during theregistration procedure over the 3GPP access. The UE 100 may provide theUE's usage setting based on its configuration. In case of initialregistration or mobility registration update, the UE 100 may include themapping of requested NSSAI, which may be the mapping of each S-NSSAI ofthe requested NSSAI to the S-NSSAIs of the configured NSSAI for theHPLMN, to ensure that the network is able to verify whether theS-NSSAI(s) in the requested NSSAI are permitted based on the subscribedS-NSSAIs. If available, the last visited TAI may be included in order tohelp the AMF 155 produce registration area for the UE. In an example,the security parameters may be used for authentication and integrityprotection. requested NSSAI may indicate the network slice selectionassistance information. The PDU session status may indicates thepreviously established PDU sessions in the UE. When the UE 100 isconnected to the two AMF 155 belonging to different PLMN via 3GPP accessand non-3GPP access then the PDU session status may indicate theestablished PDU session of the current PLMN in the UE. The PDUsession(s) to be re-activated may be included to indicate the PDUsession(s) for which the UE 100 may intend to activate UP connections. APDU session corresponding to a LADN may not be included in the PDUsession(s) to be re-activated when the UE 100 is outside the area ofavailability of the LADN. The follow on request may be included when theUE 100 may have pending uplink signaling and the UE 100 may not includePDU session(s) to be re-activated, or the registration type may indicatethe UE 100 may want to perform an emergency registration.

In an example, if a SUPI is included or the 5G-GUTI does not indicate avalid AMF 155, the (R)AN 105, based on (R)AT and requested NSSAI, ifavailable, may selects 808 an AMF 155. If UE 100 is in CM-CONNECTEDstate, the (R)AN 105 may forward the registration request message to theAMF 155 based on the N2 connection of the UE. If the (R)AN 105 may notselect an appropriate AMF 155, it may forward the registration requestto an AMF 155 which has been configured, in (R)AN 105, to perform AMF155 selection 808.

In an example, the (R)AN 105 may send to the new AMF 155 an N2 message810 (comprising: N2 parameters, RM-NAS registration request(registration type, SUPI or 5G-GUTI, last visited TAI (if available),security parameters, requested NSSAI, mapping of requested NSSAI, UE 1005GC capability, PDU session status, PDU session(s) to be re-activated,follow on request, and MICO mode preference), and/or the like). In anexample, when NG-RAN is used, the N2 parameters may comprise theselected PLMN ID, location information, cell identity and the RAT typerelated to the cell in which the UE 100 is camping. In an example, whenNG-RAN is used, the N2 parameters may include the establishment cause.

In an example, the new AMF 155 may send to the old AMF 155 aNamf_Communication_UEContextTransfer (complete registration request)815. In an example, if the UE's 5G-GUTI was included in the registrationrequest and the serving AMF 155 has changed since last registrationprocedure, the new AMF 155 may invoke theNamf_Communication_UEContextTransfer service operation 815 on the oldAMF 155 including the complete registration request IE, which may beintegrity protected, to request the UE's SUPI and MM Context. The oldAMF 155 may use the integrity protected complete registration request IEto verify if the context transfer service operation invocationcorresponds to the UE 100 requested. In an example, the old AMF 155 maytransfer the event subscriptions information by each NF consumer, forthe UE, to the new AMF 155. In an example, if the UE 100 identifiesitself with PEI, the SUPI request may be skipped.

In an example, the old AMF 155 may send to new AMF 155 a response 815 toNamf_Communication_UEContextTransfer (SUPI, MM context, SMF 160information, PCF ID). In an example, the old AMF 155 may respond to thenew AMF 155 for the Namf_Communication_UEContextTransfer invocation byincluding the UE's SUPI and MM context. In an example, if old AMF 155holds information about established PDU sessions, the old AMF 155 mayinclude SMF 160 information including S-NSSAI(s), SMF 160 identities andPDU session ID. In an example, if old AMF 155 holds information aboutactive NGAP UE-TNLA bindings to N3IWF, the old AMF 155 may includeinformation about the NGAP UE-TNLA bindings.

In an example, if the SUPI is not provided by the UE 100 nor retrievedfrom the old AMF 155 the identity request procedure 820 may be initiatedby the AMF 155 sending an identity request message to the UE 100requesting the SUCI.

In an example, the UE 100 may respond with an identity response message820 including the SUCI. The UE 100 may derive the SUCI by using theprovisioned public key of the HPLMN.

In an example, the AMF 155 may decide to initiate UE 100 authentication825 by invoking an AUSF 150. The AMF 155 may select an AUSF 150 based onSUPI or SUCI. In an example, if the AMF 155 is configured to supportemergency registration for unauthenticated SUPIs and the UE 100indicated registration type emergency registration the AMF 155 may skipthe authentication and security setup or the AMF 155 may accept that theauthentication may fail and may continue the registration procedure.

In an example, the authentication 830 may be performed byNudm_UEAuthenticate_Get operation. The AUSF 150 may discover a UDM 140.In case the AMF 155 provided a SUCI to AUSF 150, the AUSF 150 may returnthe SUPI to AMF 155 after the authentication is successful. In anexample, if network slicing is used, the AMF 155 may decide if theregistration request needs to be rerouted where the initial AMF 155refers to the AMF 155. In an example, the AMF 155 may initiate NASsecurity functions. In an example, upon completion of NAS securityfunction setup, the AMF 155 may initiate NGAP procedure to enable 5G-ANuse it for securing procedures with the UE. In an example, the 5G-AN maystore the security context and may acknowledge to the AMF 155. The 5G-ANmay use the security context to protect the messages exchanged with theUE.

In an example, new AMF 155 may send to the old AMF 155Namf_Communication_RegistrationCompleteNotify 835. If the AMF 155 haschanged, the new AMF 155 may notify the old AMF 155 that theregistration of the UE 100 in the new AMF 155 may be completed byinvoking the Namf_Communication_RegistrationCompleteNotify serviceoperation. If the authentication/security procedure fails, then theregistration may be rejected, and the new AMF 155 may invoke theNamf_Communication_RegistrationCompleteNotify service operation with areject indication reason code towards the old AMF 155. The old AMF 155may continue as if the UE 100 context transfer service operation wasnever received. If one or more of the S-NSSAIs used in the oldregistration area may not be served in the target registration area, thenew AMF 155 may determine which PDU session may not be supported in thenew registration area. The new AMF 155 may invoke theNamf_Communication_RegistrationCompleteNotify service operationincluding the rejected PDU session ID and a reject cause (e.g. theS-NSSAI becomes no longer available) towards the old AMF 155. The newAMF 155 may modify the PDU session status correspondingly. The old AMF155 may inform the corresponding SMF 160(s) to locally release the UE'sSM context by invoking the Nsmf_PDUSession_ReleaseSMContext serviceoperation.

In an example, the new AMF 155 may send to the UE 100 an identityrequest/response 840 (e.g., PEI). If the PEI was not provided by the UE100 nor retrieved from the old AMF 155, the identity request proceduremay be initiated by AMF 155 sending an identity request message to theUE 100 to retrieve the PEI. The PEI may be transferred encrypted unlessthe UE 100 performs emergency registration and may not be authenticated.For an emergency registration, the UE 100 may have included the PEI inthe registration request.

In an example, the new AMF 155 may initiate ME identity check 845 byinvoking the N5g-eir_EquipmentIdentityCheck_Get service operation 845.

In an example, the new AMF 155, based on the SUPI, may select 905 a UDM140. The UDM 140 may select a UDR instance. In an example, the AMF 155may select a UDM 140.

In an example, if the AMF 155 has changed since the last registrationprocedure, or if the UE 100 provides a SUPI which may not refer to avalid context in the AMF 155, or if the UE 100 registers to the same AMF155 it has already registered to a non-3GPP access (e.g., the UE 100 isregistered over a non-3GPP access and may initiate the registrationprocedure to add a 3GPP access), the new AMF 155 may register with theUDM 140 using Nudm_UECM_Registration 910 and may subscribe to benotified when the UDM 140 may deregister the AMF 155. The UDM 140 maystore the AMF 155 identity associated to the access type and may notremove the AMF 155 identity associated to the other access type. The UDM140 may store information provided at registration in UDR, byNudr_UDM_Update. In an example, the AMF 155 may retrieve the access andmobility subscription data and SMF 160 selection subscription data usingNudm_SDM_Get 915. The UDM 140 may retrieve this information from UDR byNudr_UDM_Query (access and mobility subscription data). After asuccessful response is received, the AMF 155 may subscribe to benotified using Nudm_SDM_Subscribe 920 when the data requested may bemodified. The UDM 140 may subscribe to UDR by Nudr_UDM_Subscribe. TheGPSI may be provided to the AMF 155 in the subscription data from theUDM 140 if the GPSI is available in the UE 100 subscription data. In anexample, the new AMF 155 may provide the access type it serves for theUE 100 to the UDM 140 and the access type may be set to 3GPP access. TheUDM 140 may store the associated access type together with the servingAMF 155 in UDR by Nudr_UDM_Update. The new AMF 155 may create an MMcontext for the UE 100 after getting the mobility subscription data fromthe UDM 140. In an example, when the UDM 140 stores the associatedaccess type together with the serving AMF 155, the UDM 140 may initiatea Nudm_UECM_DeregistrationNotification 921 to the old AMF 155corresponding to 3GPP access. The old AMF 155 may remove the MM contextof the UE. If the serving NF removal reason indicated by the UDM 140 isinitial registration, then the old AMF 155 may invoke theNamf_EventExposure_Notify service operation towards all the associatedSMF 160 s of the UE 100 to notify that the UE 100 is deregistered fromold AMF 155. The SMF 160 may release the PDU session(s) on getting thisnotification. In an example, the old AMF 155 may unsubscribe with theUDM 140 for subscription data using Nudm_SDM_unsubscribe 922.

In an example, if the AMF 155 decides to initiate PCF 135 communication,e.g. the AMF 155 has not yet obtained access and mobility policy for theUE 100 or if the access and mobility policy in the AMF 155 are no longervalid, the AMF 155 may select 925 a PCF 135. If the new AMF 155 receivesa PCF ID from the old AMF 155 and successfully contacts the PCF 135identified by the PCF ID, the AMF 155 may select the (V-)PCF identifiedby the PCF ID. If the PCF 135 identified by the PCF ID may not be used(e.g. no response from the PCF 135) or if there is no PCF ID receivedfrom the old AMF 155, the AMF 155 may select 925 a PCF 135.

In an example, the new AMF 155 may perform a policy associationestablishment 930 during registration procedure. If the new AMF 155contacts the PCF 135 identified by the (V-)PCF ID received duringinter-AMF 155 mobility, the new AMF 155 may include the PCF-ID in theNpcf_AMPolicyControl Get operation. If the AMF 155 notifies the mobilityrestrictions (e.g. UE 100 location) to the PCF 135 for adjustment, or ifthe PCF 135 updates the mobility restrictions itself due to someconditions (e.g. application in use, time and date), the PCF 135 mayprovide the updated mobility restrictions to the AMF 155.

In an example, the PCF 135 may invoke Namf_EventExposure_Subscribeservice operation 935 for UE 100 event subscription.

In an example, the AMF 155 may send to the SMF 160 aNsmf_PDUSession_UpdateSMContext 936. In an example, the AMF 155 mayinvoke the Nsmf_PDUSession_UpdateSMContext if the PDU session(s) to bere-activated is included in the registration request. The AMF 155 maysend Nsmf_PDUSession_UpdateSMContext request to SMF 160(s) associatedwith the PDU session(s) to activate user plane connections of the PDUsession(s). The SMF 160 may decide to trigger e.g. the intermediate UPF110 insertion, removal or change of PSA. In the case that theintermediate UPF 110 insertion, removal, or relocation is performed forthe PDU session(s) not included in PDU session(s) to be re-activated,the procedure may be performed without N11 and N2 interactions to updatethe N3 user plane between (R)AN 105 and 5GC. The AMF 155 may invoke theNsmf_PDUSession_ReleaseSMContext service operation towards the SMF 160if any PDU session status indicates that it is released at the UE 100.The AMF 155 may invoke the Nsmf_PDUSession_ReleaseSMContext serviceoperation towards the SMF 160 in order to release any network resourcesrelated to the PDU session.

In an example, the new AMF 155 may send to a N3IWF an N2 AMF 155mobility request 940. If the AMF 155 has changed, the new AMF 155 maycreate an NGAP UE 100 association towards the N3IWF to which the UE 100is connected. In an example, the N3IWF may respond to the new AMF 155with an N2 AMF 155 mobility response 940.

In an example, the new AMF 155 may send to the UE 100 a registrationaccept 955 (comprising: 5G-GUTI, registration area, mobilityrestrictions, PDU session status, allowed NSSAI, [mapping of allowedNSSAI], periodic registration update timer, LADN information andaccepted MICO mode, IMS voice over PS session supported indication,emergency service support indicator, and/or the like). In an example,the AMF 155 may send the registration accept message to the UE 100indicating that the registration request has been accepted. 5G-GUTI maybe included if the AMF 155 allocates a new 5G-GUTI. If the AMF 155allocates a new registration area, it may send the registration area tothe UE 100 via registration accept message 955. If there is noregistration area included in the registration accept message, the UE100 may consider the old registration area as valid. In an example,mobility restrictions may be included in case mobility restrictions mayapply for the UE 100 and registration type may not be emergencyregistration. The AMF 155 may indicate the established PDU sessions tothe UE 100 in the PDU session status. The UE 100 may remove locally anyinternal resources related to PDU sessions that are not marked asestablished in the received PDU session status. In an example, when theUE 100 is connected to the two AMF 155 belonging to different PLMN via3GPP access and non-3GPP access then the UE 100 may remove locally anyinternal resources related to the PDU session of the current PLMN thatare not marked as established in received PDU session status. If the PDUsession status information was in the registration request, the AMF 155may indicate the PDU session status to the UE. The mapping of allowedNSSAI may be the mapping of each S-NSSAI of the allowed NSSAI to theS-NSSAIs of the configured NSSAI for the HPLMN. The AMF 155 may includein the registration accept message 955 the LADN information for LADNsthat are available within the registration area determined by the AMF155 for the UE. If the UE 100 included MICO mode in the request, thenAMF 155 may respond whether MICO mode may be used. The AMF 155 may setthe IMS voice over PS session supported Indication. In an example, inorder to set the IMS voice over PS session supported indication, the AMF155 may perform a UE/RAN radio information and compatibility requestprocedure to check the compatibility of the UE 100 and RAN radiocapabilities related to IMS voice over PS. In an example, the emergencyservice support indicator may inform the UE 100 that emergency servicesare supported, e.g., the UE 100 may request PDU session for emergencyservices. In an example, the handover restriction list and UE-AMBR maybe provided to NG-RAN by the AMF 155.

In an example, the UE 100 may send to the new AMF 155 a registrationcomplete 960 message. In an example, the UE 100 may send theregistration complete message 960 to the AMF 155 to acknowledge that anew 5G-GUTI may be assigned. In an example, when information about thePDU session(s) to be re-activated is not included in the registrationrequest, the AMF 155 may release the signaling connection with the UE100. In an example, when the follow-on request is included in theregistration request, the AMF 155 may not release the signalingconnection after the completion of the registration procedure. In anexample, if the AMF 155 is aware that some signaling is pending in theAMF 155 or between the UE 100 and the 5GC, the AMF 155 may not releasethe signaling connection after the completion of the registrationprocedure.

As depicted in example FIG. 10 and FIG. 11 , a service request proceduree.g., a UE 100 triggered service request procedure may be used by a UE100 in CM-IDLE state to request the establishment of a secure connectionto an AMF 155. FIG. 11 is continuation of FIG. 10 depicting the servicerequest procedure. The service request procedure may be used to activatea user plane connection for an established PDU session. The servicerequest procedure may be triggered by the UE 100 or the 5GC, and may beused when the UE 100 is in CM-IDLE and/or in CM-CONNECTED and may allowselectively to activate user plane connections for some of theestablished PDU sessions.

In an example, a UE 100 in CM IDLE state may initiate the servicerequest procedure to send uplink signaling messages, user data, and/orthe like, as a response to a network paging request, and/or the like. Inan example, after receiving the service request message, the AMF 155 mayperform authentication. In an example, after the establishment ofsignaling connection to the AMF 155, the UE 100 or network may sendsignaling messages, e.g. PDU session establishment from the UE 100 to aSMF 160, via the AMF 155.

In an example, for any service request, the AMF 155 may respond with aservice accept message to synchronize PDU session status between the UE100 and network. The AMF 155 may respond with a service reject messageto the UE 100, if the service request may not be accepted by thenetwork. The service reject message may include an indication or causecode requesting the UE 100 to perform a registration update procedure.In an example, for service request due to user data, network may takefurther actions if user plane connection activation may not besuccessful. In an example FIG. 10 and FIG. 11 , more than one UPF, e.g.,old UPF 110-2 and PDU session Anchor PSA UPF 110-3 may be involved.

In an example, the UE 100 may send to a (R)AN 105 an AN messagecomprising AN parameters, mobility management, MM NAS service request1005 (e.g., list of PDU sessions to be activated, list of allowed PDUsessions, security parameters, PDU session status, and/or the like),and/or the like. In an example, the UE 100 may provide the list of PDUsessions to be activated when the UE 100 may re-activate the PDUsession(s). The list of allowed PDU sessions may be provided by the UE100 when the service request may be a response of a paging or a NASnotification, and may identify the PDU sessions that may be transferredor associated to the access on which the service request may be sent. Inan example, for the case of NG-RAN, the AN parameters may includeselected PLMN ID, and an establishment cause. The establishment causemay provide the reason for requesting the establishment of an RRCconnection. The UE 100 may send NAS service request message towards theAMF 155 encapsulated in an RRC message to the RAN 105.

In an example, if the service request may be triggered for user data,the UE 100 may identify, using the list of PDU sessions to be activated,the PDU session(s) for which the UP connections are to be activated inthe NAS service request message. If the service request may be triggeredfor signaling, the UE 100 may not identify any PDU session(s). If thisprocedure may be triggered for paging response, and/or the UE 100 mayhave at the same time user data to be transferred, the UE 100 mayidentify the PDU session(s) whose UP connections may be activated in MMNAS service request message, by the list of PDU sessions to beactivated.

In an example, if the service request over 3GPP access may be triggeredin response to a paging indicating non-3GPP access, the NAS servicerequest message may identify in the list of allowed PDU sessions thelist of PDU sessions associated with the non-3GPP access that may bere-activated over 3GPP. In an example, the PDU session status mayindicate the PDU sessions available in the UE 100. In an example, the UE100 may not trigger the service request procedure for a PDU sessioncorresponding to a LADN when the UE 100 may be outside the area ofavailability of the LADN. The UE 100 may not identify such PDUsession(s) in the list of PDU sessions to be activated, if the servicerequest may be triggered for other reasons.

In an example, the (R)AN 105 may send to AMF 155 an N2 Message 1010(e.g., a service request) comprising N2 parameters, MM NAS servicerequest, and/or the like. The AMF 155 may reject the N2 message if itmay not be able to handle the service request. In an example, if NG-RANmay be used, the N2 parameters may include the 5G-GUTI, selected PLMNID, location information, RAT type, establishment cause, and/or thelike. In an example, the 5G-GUTI may be obtained in RRC procedure andthe (R)AN 105 may select the AMF 155 according to the 5G-GUTI. In anexample, the location information and RAT type may relate to the cell inwhich the UE 100 may be camping. In an example, based on the PDU sessionstatus, the AMF 155 may initiate PDU session release procedure in thenetwork for the PDU sessions whose PDU session ID(s) may be indicated bythe UE 100 as not available.

In an example, if the service request was not sent integrity protectedor integrity protection verification failed, the AMF 155 may initiate aNAS authentication/security procedure 1015.

In an example, if the UE 100 triggers the service request to establish asignaling connection, upon successful establishment of the signalingconnection, the UE 100 and the network may exchange NAS signaling.

In an example the AMF 155 may send to the SMF 160 a PDU session updatecontext request 1020 e.g., Nsmf_PDUSession_UpdateSMContext requestcomprising PDU session ID(s), Cause(s), UE 100 location information,access type, and/or the like.

In an example, the Nsmf_PDUSession_UpdateSMContext request may beinvoked by the AMF 155 if the UE 100 may identify PDU session(s) to beactivated in the NAS service request message. In an example, theNsmf_PDUSession_UpdateSMContext request may be triggered by the SMF 160wherein the PDU session(s) identified by the UE 100 may correlate toother PDU session ID(s) than the one triggering the procedure. In anexample, the Nsmf_PDUSession_UpdateSMContext request may be triggered bythe SMF 160 wherein the current UE 100 location may be outside the areaof validity for the N2 information provided by the SMF 160 during anetwork triggered service request procedure. The AMF 155 may not sendthe N2 information provided by the SMF 160 during the network triggeredservice request procedure.

In an example, the AMF 155 may determine the PDU session(s) to beactivated and may send a Nsmf_PDUSession_UpdateSMContext request to SMF160(s) associated with the PDU session(s) with cause set to indicateestablishment of user plane resources for the PDU session(s).

In an example, if the procedure may be triggered in response to pagingindicating non-3GPP access, and the list of allowed PDU sessionsprovided by the UE 100 may not include the PDU session for which the UE100 was paged, the AMF 155 may notify the SMF 160 that the user planefor the PDU session may not be re-activated. The service requestprocedure may succeed without re-activating the user plane of any PDUsessions, and the AMF 155 may notify the UE 100.

In an example, if the PDU session ID may correspond to a LADN and theSMF 160 may determine that the UE 100 may be outside the area ofavailability of the LADN based on the UE 100 location reporting from theAMF 155, the SMF 160 may decide to (based on local policies) keep thePDU session, may reject the activation of user plane connection for thePDU session and may inform the AMF 155. In an example, if the proceduremay be triggered by a network triggered service request, the SMF 160 maynotify the UPF 110 that originated the data notification to discarddownlink data for the PDU sessions and/or to not provide further datanotification messages. The SMF 160 may respond to the AMF 155 with anappropriate reject cause and the user plane activation of PDU sessionmay be stopped.

In an example, if the PDU session ID may correspond to a LADN and theSMF 160 may determine that the UE 100 may be outside the area ofavailability of the LADN based on the UE 100 location reporting from theAMF 155, the SMF 160 may decide to (based on local policies) release thePDU session. The SMF 160 may locally release the PDU session and mayinform the AMF 155 that the PDU session may be released. The SMF 160 mayrespond to the AMF 155 with an appropriate reject cause and the userplane Activation of PDU session may be stopped.

In an example, if the UP activation of the PDU session may be acceptedby the SMF 160, based on the location info received from the AMF 155,the SMF 160 may check the UPF 110 Selection 1025 Criteria (e.g., sliceisolation requirements, slice coexistence requirements, UPF's 110dynamic load, UPF's 110 relative static capacity among UPFs supportingthe same DNN, UPF 110 location available at the SMF 160, UE 100 locationinformation, Capability of the UPF 110 and the functionality requiredfor the particular UE 100 session. In an example, an appropriate UPF 110may be selected by matching the functionality and features required fora UE 100, DNN, PDU session type (e.g. IPv4, IPv6, ethernet type orunstructured type) and if applicable, the static IP address/prefix, SSCmode selected for the PDU session, UE 100 subscription profile in UDM140, DNAI as included in the PCC rules, local operator policies,S-NSSAI, access technology being used by the UE 100, UPF 110 logicaltopology, and/or the like), and may determine to perform one or more ofthe following: continue using the current UPF(s); may select a newintermediate UPF 110 (or add/remove an intermediate UPF 110), if the UE100 has moved out of the service area of the UPF 110 that was previouslyconnecting to the (R)AN 105, while maintaining the UPF(s) acting as PDUsession anchor; may trigger re-establishment of the PDU session toperform relocation/reallocation of the UPF 110 acting as PDU sessionanchor, e.g. the UE 100 has moved out of the service area of the anchorUPF 110 which is connecting to RAN 105.

In an example, the SMF 160 may send to the UPF 110 (e.g., newintermediate UPF 110) an N4 session establishment request 1030. In anexample, if the SMF 160 may select a new UPF 110 to act as intermediateUPF 110-2 for the PDU session, or if the SMF 160 may select to insert anintermediate UPF 110 for a PDU session which may not have anintermediate UPF 110-2, an N4 session establishment request 1030 messagemay be sent to the new UPF 110, providing packet detection, dataforwarding, enforcement and reporting rules to be installed on the newintermediate UPF. The PDU session anchor addressing information (on N9)for this PDU session may be provided to the intermediate UPF 110-2.

In an example, if a new UPF 110 is selected by the SMF 160 to replacethe old (intermediate) UPF 110-2, the SMF 160 may include a dataforwarding indication. The data forwarding indication may indicate tothe UPF 110 that a second tunnel endpoint may be reserved for bufferedDL data from the old I-UPF.

In an example, the new UPF 110 (intermediate) may send to SMF 160 an N4session establishment response message 1030. In case the UPF 110 mayallocate CN tunnel info, the UPF 110 may provide DL CN tunnel info forthe UPF 110 acting as PDU session anchor and UL CN tunnel info (e.g., CNN3 tunnel info) to the SMF 160. If the data forwarding indication may bereceived, the new (intermediate) UPF 110 acting as N3 terminating pointmay send DL CN tunnel info for the old (intermediate) UPF 110-2 to theSMF 160. The SMF 160 may start a timer, to release the resource in theold intermediate UPF 110-2.

In an example, if the SMF 160 may selects a new intermediate UPF 110 forthe PDU session or may remove the old I-UPF 110-2, the SMF 160 may sendN4 session modification request message 1035 to PDU session anchor, PSAUPF 110-3, providing the data forwarding indication and DL tunnelinformation from new intermediate UPF 110.

In an example, if the new intermediate UPF 110 may be added for the PDUsession, the (PSA) UPF 110-3 may begin to send the DL data to the newI-UPF 110 as indicated in the DL tunnel information.

In an example, if the service request may be triggered by the network,and the SMF 160 may remove the old I-UPF 110-2 and may not replace theold I-UPF 110-2 with the new I-UPF 110, the SMF 160 may include the dataforwarding indication in the request. The data forwarding indication mayindicate to the (PSA) UPF 110-3 that a second tunnel endpoint may bereserved for buffered DL data from the old I-UPF 110-2. In this case,the PSA UPF 110-3 may begin to buffer the DL data it may receive at thesame time from the N6 interface.

In an example, the PSA UPF 110-3 (PSA) may send to the SMF 160 an N4session modification response 1035. In an example, if the dataforwarding indication may be received, the PSA UPF 110-3 may become asN3 terminating point and may send CN DL tunnel info for the old(intermediate) UPF 110-2 to the SMF 160. The SMF 160 may start a timer,to release the resource in old intermediate UPF 110-2 if there is one.

In an example, the SMF 160 may send to the old UPF 110-2 an N4 sessionmodification request 1045 (e.g., may comprise new UPF 110 address, newUPF 110 DL tunnel ID, and/or the like). In an example, if the servicerequest may be triggered by the network, and/or the SMF 160 may removethe old (intermediate) UPF 110-2, the SMF 160 may send the N4 sessionmodification request message to the old (intermediate) UPF 110-2, andmay provide the DL tunnel information for the buffered DL data. If theSMF 160 may allocate new I-UPF 110, the DL tunnel information is fromthe new (intermediate) UPF 110 may act as N3 terminating point. If theSMF 160 may not allocate a new I-UPF 110, the DL tunnel information maybe from the new UPF 110 (PSA) 110-3 acting as N3 terminating point. TheSMF 160 may start a timer to monitor the forwarding tunnel. In anexample, the old (intermediate) UPF 110-2 may send N4 sessionmodification response message to the SMF 160.

In an example, if the I-UPF 110-2 may be relocated and forwarding tunnelwas established to the new I-UPF 110, the old (intermediate) UPF 110-2may forward its buffered data to the new (intermediate) UPF 110 actingas N3 terminating point. In an example, if the old I-UPF 110-2 may beremoved and the new I-UPF 110 may not be assigned for the PDU sessionand forwarding tunnel may be established to the UPF 110 (PSA) 110-3, theold (intermediate) UPF 110-2 may forward its buffered data to the UPF110 (PSA) 110-3 acting as N3 terminating point.

In an example, the SMF 160 may send to the AMF 155 an N11 message 1060e.g., a Nsmf_PDUSession_UpdateSMContext response (comprising: N1 SMcontainer (PDU session ID, PDU session re-establishment indication), N2SM information (PDU session ID, QoS profile, CN N3 tunnel info,S-NSSAI), Cause), upon reception of the Nsmf_PDUSession_UpdateSMContextrequest with a cause including e.g., establishment of user planeresources. The SMF 160 may determine whether UPF 110 reallocation may beperformed, based on the UE 100 location information, UPF 110 servicearea and operator policies. In an example, for a PDU session that theSMF 160 may determine to be served by the current UPF 110, e.g., PDUsession anchor or intermediate UPF, the SMF 160 may generate N2 SMinformation and may send a Nsmf_PDUSession_UpdateSMContext response 1060to the AMF 155 to establish the user plane(s). The N2 SM information maycontain information that the AMF 155 may provide to the RAN 105. In anexample, for a PDU session that the SMF 160 may determine as requiring aUPF 110 relocation for PDU session anchor UPF, the SMF 160 may rejectthe activation of UP of the PDU session by sendingNsmf_PDUSession_UpdateSMContext response that may contain N1 SMcontainer to the UE 100 via the AMF 155. The N1 SM container may includethe corresponding PDU session ID and PDU session re-establishmentindication.

Upon reception of the Namf_EventExposure_Notify from the AMF 155 to theSMF 160, with an indication that the UE 100 is reachable, if the SMF 160may have pending DL data, the SMF 160 may invoke theNamf_Communication_N1N2MessageTransfer service operation to the AMF 155to establish the user plane(s) for the PDU sessions. In an example, theSMF 160 may resume sending DL data notifications to the AMF 155 in caseof DL data.

In an example, the SMF 160 may send a message to the AMF 155 to rejectthe activation of UP of the PDU session by including a cause in theNsmf_PDUSession_UpdateSMContext response if the PDU session maycorrespond to a LADN and the UE 100 may be outside the area ofavailability of the LADN, or if the AMF 155 may notify the SMF 160 thatthe UE 100 may be reachable for regulatory prioritized service, and thePDU session to be activated may not for a regulatory prioritizedservice; or if the SMF 160 may decide to perform PSA UPF 110-3relocation for the requested PDU session.

In an example, the AMF 155 may send to the (R)AN 105 an N2 requestmessage 1065 (e.g., N2 SM information received from SMF 160, securitycontext, AMF 155 signaling connection ID, handover restriction list, MMNAS service accept, list of recommended cells/TAs/NG-RAN nodeidentifiers). In an example, the RAN 105 may store the security context,AMF 155 signaling connection Id, QoS information for the QoS flows ofthe PDU sessions that may be activated and N3 tunnel IDs in the UE 100RAN 105 context. In an example, the MM NAS service accept may includePDU session status in the AMF 155. If the activation of UP of a PDUsession may be rejected by the SMF 160, the MM NAS service accept mayinclude the PDU session ID and the reason why the user plane resourcesmay not be activated (e.g. LADN not available). Local PDU sessionrelease during the session request procedure may be indicated to the UE100 via the session Status.

In an example, if there are multiple PDU sessions that may involvemultiple SMF 160s, the AMF 155 may not wait for responses from all SMF160 s before it may send N2 SM information to the UE 100. The AMF 155may wait for all responses from the SMF 160 s before it may send MM NASservice accept message to the UE 100.

In an example, the AMF 155 may include at least one N2 SM informationfrom the SMF 160 if the procedure may be triggered for PDU session userplane activation. AMF 155 may send additional N2 SM information from SMF160 s in separate N2 message(s) (e.g. N2 tunnel setup request), if thereis any. Alternatively, if multiple SMF 160 s may be involved, the AMF155 may send one N2 request message to (R)AN 105 after all theNsmf_PDUSession_UpdateSMContext response service operations from all theSMF 160 s associated with the UE 100 may be received. In such case, theN2 request message may include the N2 SM information received in each ofthe Nsmf_PDUSession_UpdateSMContext response and PDU session ID toenable AMF 155 to associate responses to relevant SMF 160.

In an example, if the RAN 105 (e.g., NG RAN) node may provide the listof recommended cells/TAs/NG-RAN node identifiers during the AN releaseprocedure, the AMF 155 may include the information from the list in theN2 request. The RAN 105 may use this information to allocate the RAN 105notification area when the RAN 105 may decide to enable RRC inactivestate for the UE 100.

If the AMF 155 may receive an indication, from the SMF 160 during a PDUsession establishment procedure that the UE 100 may be using a PDUsession related to latency sensitive services, for any of the PDUsessions established for the UE 100 and the AMF 155 has received anindication from the UE 100 that may support the CM-CONNECTED with RRCinactive state, then the AMF 155 may include the UE's RRC inactiveassistance information. In an example, the AMF 155 based on networkconfiguration, may include the UE's RRC inactive assistance information.

In an example, the (R)AN 105 may send to the UE 100 a message to performRRC connection reconfiguration 1070 with the UE 100 depending on the QoSinformation for all the QoS flows of the PDU sessions whose UPconnections may be activated and data radio bearers. In an example, theuser plane security may be established.

In an example, if the N2 request may include a MM NAS service acceptmessage, the RAN 105 may forward the MM NAS service accept to the UE100. The UE 100 may locally delete context of PDU sessions that may notbe available in 5GC.

In an example, if the N1 SM information may be transmitted to the UE 100and may indicate that some PDU session(s) may be re-established, the UE100 may initiate PDU session re-establishment for the PDU session(s)that may be re-established after the service request procedure may becomplete.

In an example, after the user plane radio resources may be setup, theuplink data from the UE 100 may be forwarded to the RAN 105. The RAN 105(e.g., NG-RAN) may send the uplink data to the UPF 110 address andtunnel ID provided.

In an example, the (R)AN 105 may send to the AMF 155 an N2 request Ack1105 (e.g., N2 SM information (comprising: AN tunnel info, list ofaccepted QoS flows for the PDU sessions whose UP connections areactivated, list of rejected QoS flows for the PDU sessions whose UPconnections are activated)). In an example, the N2 request message mayinclude N2 SM information(s), e.g. AN tunnel info. RAN 105 may respondN2 SM information with separate N2 message (e.g. N2 tunnel setupresponse). In an example, if multiple N2 SM information are included inthe N2 request message, the N2 request Ack may include multiple N2 SMinformation and information to enable the AMF 155 to associate theresponses to relevant SMF 160.

In an example, the AMF 155 may send to the SMF 160 aNsmf_PDUSession_UpdateSMContext request 1110 (N2 SM information (ANtunnel info), RAT type) per PDU session. If the AMF 155 may receive N2SM information (one or multiple) from the RAN 105, then the AMF 155 mayforward the N2 SM information to the relevant SMF 160. If the UE 100time zone may change compared to the last reported UE 100 Time Zone,then the AMF 155 may include the UE 100 time zone IE in theNsmf_PDUSession_UpdateSMContext request message.

In an example, if dynamic PCC is deployed, the SMF 160 may initiatenotification about new location information to the PCF 135 (ifsubscribed) by invoking an event exposure notification operation (e.g.,a Nsmf_EventExposure_Notify service operation). The PCF 135 may provideupdated policies by invoking a policy control update notificationmessage 1115 (e.g., a Npcf_SMPolicyControl_UpdateNotify operation).

In an example, if the SMF 160 may select a new UPF 110 to act asintermediate UPF 110 for the PDU session, the SMF 160 may initiates anN4 session modification procedure 1120 to the new I-UPF 110 and mayprovide AN tunnel info. The downlink data from the new I-UPF 110 may beforwarded to RAN 105 and UE 100. In an example, the UPF 110 may send tothe SMF 160, an N4 session modification response 1120. In an example,the SMF 160 may send to the AMF 155, a Nsmf_PDUSession_UpdateSMContextresponse 1140.

In an example, if forwarding tunnel may be established to the new I-UPF110 and if the timer SMF 160 set for forwarding tunnel may be expired,the SMF 160 may sends N4 session modification request 1145 to new(intermediate) UPF 110 acting as N3 terminating point to release theforwarding tunnel. In an example, the new (intermediate) UPF 110 maysend to the SMF 160 an N4 session modification response 1145. In anexample, the SMF 160 may send to the PSA UPF 110-3 an N4 sessionmodification request 1150, or N4 session release request. In an example,if the SMF 160 may continue using the old UPF 110-2, the SMF 160 maysend an N4 session modification request 1155, providing AN tunnel info.In an example, if the SMF 160 may select a new UPF 110 to act asintermediate UPF 110, and the old UPF 110-2 may not be PSA UPF 110-3,the SMF 160 may initiate resource release, after timer expires, bysending an N4 session release request (release cause) to the oldintermediate UPF 110-2.

In an example, the old intermediate UPF 110-2 may send to the SMF 160 anN4 session modification response or N4 session release response 1155.The old UPF 110-2 may acknowledge with the N4 session modificationresponse or N4 session release response message to confirm themodification or release of resources. The AMF 155 may invoke theNamf_EventExposure_Notify service operation to notify the mobilityrelated events, after this procedure may complete, towards the NFs thatmay have subscribed for the events. In an example, the AMF 155 mayinvoke the Namf_EventExposure_Notify towards the SMF 160 if the SMF 160had subscribed for UE 100 moving into or out of area of interest and ifthe UE's current location may indicate that it may be moving into ormoving outside of the area of interest subscribed, or if the SMF 160 hadsubscribed for LADN DNN and if the UE 100 may be moving into or outsideof an area where the LADN is available, or if the UE 100 may be in MICOmode and the AMF 155 had notified an SMF 160 of the UE 100 beingunreachable and that SMF 160 may not send DL data notifications to theAMF 155, and the AMF 155 may informs the SMF 160 that the UE 100 isreachable, or if the SMF 160 had subscribed for UE 100 reachabilitystatus, then the AMF 155 may notify the UE 100 reachability.

An example PDU session establishment procedure depicted in FIG. 12 andFIG. 13 . In an example embodiment, when the PDU session establishmentprocedure may be employed, the UE 100 may send to the AMF 155 a NASMessage 1205 (or a SM NAS message) comprising NSSAI, S-NSSAI (e.g.,requested S-NSSAI, allowed S-NSSAI, subscribed S-NSSAI, and/or thelike), DNN, PDU session ID, request type, old PDU session ID, N1 SMcontainer (PDU session establishment request), and/or the like. In anexample, the UE 100, in order to establish a new PDU session, maygenerate a new PDU session ID. In an example, when emergency service maybe required and an emergency PDU session may not already be established,the UE 100 may initiate the UE 100 requested PDU session establishmentprocedure with a request type indicating emergency request. In anexample, the UE 100 may initiate the UE 100 requested PDU sessionestablishment procedure by the transmission of the NAS messagecontaining a PDU session establishment request within the N1 SMcontainer. The PDU session establishment request may include a PDU type,SSC mode, protocol configuration options, and/or the like. In anexample, the request type may indicate initial request if the PDUsession establishment is a request to establish the new PDU session andmay indicate existing PDU session if the request refers to an existingPDU session between 3GPP access and non-3GPP access or to an existingPDN connection in EPC. In an example, the request type may indicateemergency request if the PDU session establishment may be a request toestablish a PDU session for emergency services. The request type mayindicate existing emergency PDU session if the request refers to anexisting PDU session for emergency services between 3GPP access andnon-3GPP access. In an example, the NAS message sent by the UE 100 maybe encapsulated by the AN in a N2 message towards the AMF 155 that mayinclude user location information and access technology typeinformation. In an example, the PDU session establishment requestmessage may contain SM PDU DN request container containing informationfor the PDU session authorization by the external DN. In an example, ifthe procedure may be triggered for SSC mode 3 operation, the UE 100 mayinclude the old PDU session ID which may indicate the PDU session ID ofthe on-going PDU session to be released, in the NAS message. The old PDUsession ID may be an optional parameter which may be included in thiscase. In an example, the AMF 155 may receive from the AN the NAS message(e.g., NAS SM message) together with user location information (e.g.cell ID in case of the RAN 105). In an example, the UE 100 may nottrigger a PDU session establishment for a PDU session corresponding to aLADN when the UE 100 is outside the area of availability of the LADN.

In an example, the AMF 155 may determine that the NAS message or the SMNAS message may correspond to the request for the new PDU session basedon that request type indicates initial request and that the PDU sessionID may not be used for any existing PDU session(s) of the UE 100. If theNAS message does not contain an S-NSSAI, the AMF 155 may determine adefault S-NSSAI for the requested PDU session either according to the UE100 subscription, if it may contain only one default S-NSSAI, or basedon operator policy. In an example, the AMF 155 may perform SMF 160selection 1210 and select an SMF 160. If the request type may indicateinitial request or the request may be due to handover from EPS, the AMF155 may store an association of the S-NSSAI, the PDU session ID and aSMF 160 ID. In an example, if the request type is initial request and ifthe old PDU session ID indicating the existing PDU session may becontained in the message, the AMF 155 may select the SMF 160 and maystore an association of the new PDU session ID and the selected SMF 160ID.

In an example, the AMF 155 may send to the SMF 160, an N11 message 1215,e.g., Nsmf_PDUSession_CreateSMContext request (comprising: SUPI or PEI,DNN, S-NSSAI, PDU session ID, AMF 155 ID, request type, N1 SM container(PDU session establishment request), user location information, accesstype, PEI, GPSI), or Nsmf_PDUSession_UpdateSMContext request (SUPI, DNN,S-NSSAI, PDU session ID, AMF 155 ID, request type, N1 SM container (PDUsession establishment request), user location information, access type,RAT type, PEI). In an example, if the AMF 155 may not have anassociation with the SMF 160 for the PDU session ID provided by the UE100 (e.g. when request type indicates initial request), the AMF 155 mayinvoke the Nsmf_PDUSession_CreateSMContext request, but if the AMF 155already has an association with an SMF 160 for the PDU session IDprovided by the UE 100 (e.g. when request type indicates existing PDUsession), the AMF 155 may invoke the Nsmf_PDUSession_UpdateSMContextrequest. In an example, the AMF 155 ID may be the UE's GUAMI whichuniquely identifies the AMF 155 serving the UE 100. The AMF 155 mayforward the PDU session ID together with the N1 SM container containingthe PDU session establishment request received from the UE 100. The AMF155 may provide the PEI instead of the SUPI when the UE 100 hasregistered for emergency services without providing the SUPI. In casethe UE 100 has registered for emergency services but has not beenauthenticated, the AMF 155 may indicate that the SUPI has not beenauthenticated.

In an example, if the request type may indicate neither emergencyrequest nor existing emergency PDU session and, if the SMF 160 has notyet registered and subscription data may not be available, the SMF 160may register with the UDM 140, and may retrieve subscription data 1225and subscribes to be notified when subscription data may be modified. Inan example, if the request type may indicate existing PDU session orexisting emergency PDU session, the SMF 160 may determine that therequest may be due to handover between 3GPP access and non-3GPP accessor due to handover from EPS. The SMF 160 may identify the existing PDUsession based on the PDU session ID. The SMF 160 may not create a new SMcontext but instead may update the existing SM context and may providethe representation of the updated SM context to the AMF 155 in theresponse. if the request type may be initial request and if the old PDUsession ID may be included in Nsmf_PDUSession_CreateSMContext request,the SMF 160 may identify the existing PDU session to be released basedon the old PDU session ID.

In an example, the SMF 160 may send to the AMF 155, the N11 messageresponse 1220, e.g., either a PDU session create/update response,Nsmf_PDUSession_CreateSMContext response 1220 (cause, SM context ID orN1 SM container (PDU session reject(cause))) or aNsmf_PDUSession_UpdateSMContext response.

In an example, if the SMF 160 may perform secondaryauthorization/authentication 1230 during the establishment of the PDUsession by a DN-AAA server, the SMF 160 may select a UPF 110 and maytrigger a PDU session establishment authentication/authorization.

In an example, if the request type may indicate initial request, the SMF160 may select an SSC mode for the PDU session. The SMF 160 may selectone or more UPFs as needed. In case of PDU type IPv4 or IPv6, the SMF160 may allocate an IP address/prefix for the PDU session. In case ofPDU type IPv6, the SMF 160 may allocate an interface identifier to theUE 100 for the UE 100 to build its link-local address. For UnstructuredPDU type the SMF 160 may allocate an IPv6 prefix for the PDU session andN6 point-to-point tunneling (based on UDP/IPv6).

In an example, if dynamic PCC is deployed, the may SMF 160 performs PCF135 selection 1235. If the request type indicates existing PDU sessionor existing emergency PDU session, the SMF 160 may use the PCF 135already selected for the PDU session. If dynamic PCC is not deployed,the SMF 160 may apply local policy.

In an example, the SMF 160 may perform a session management policyestablishment procedure 1240 to establish a PDU session with the PCF 135and may get the default PCC Rules for the PDU session. The GPSI may beincluded if available at the SMF 160. If the request type in 1215indicates existing PDU session, the SMF 160 may notify an eventpreviously subscribed by the PCF 135 by a session management policymodification procedure and the PCF 135 may update policy information inthe SMF 160. The PCF 135 may provide authorized session-AMBR and theauthorized 5QI and ARP to SMF 160. The PCF 135 may subscribe to the IPallocation/release event in the SMF 160 (and may subscribe otherevents).

In an example, the PCF 135, based on the emergency DNN, may set the ARPof the PCC rules to a value that may be reserved for emergency services.

In an example, if the request type in 1215 indicates initial request,the SMF 160 may select an SSC mode for the PDU session. The SMF 160 mayselect 1245 one or more UPFs as needed. In case of PDU type IPv4 orIPv6, the SMF 160 may allocate an IP address/prefix for the PDU session.In case of PDU type IPv6, the SMF 160 may allocate an interfaceidentifier to the UE 100 for the UE 100 to build its link-local address.For unstructured PDU type the SMF 160 may allocate an IPv6 prefix forthe PDU session and N6 point-to-point tunneling (e.g., based onUDP/IPv6). In an example, for Ethernet PDU type PDU session, neither aMAC nor an IP address may be allocated by the SMF 160 to the UE 100 forthis PDU session.

In an example, if the request type in 1215 is existing PDU session, theSMF 160 may maintain the same IP address/prefix that may be allocated tothe UE 100 in the source network.

In an example, if the request type in 1215 indicates existing PDUsession referring to an existing PDU session moved between 3GPP accessand non-3GPP access, the SMF 160 may maintain the SSC mode of the PDUsession, e.g., the current PDU session Anchor and IP address. In anexample, the SMF 160 may trigger e.g. new intermediate UPF 110 insertionor allocation of a new UPF 110. In an example, if the request typeindicates emergency request, the SMF 160 may select 1245 the UPF 110 andmay select SSC mode 1.

In an example, the SMF 160 may perform a session management policymodification 1250 procedure to report some event to the PCF 135 that haspreviously subscribed. If request type is initial request and dynamicPCC is deployed and PDU type is IPv4 or IPv6, the SMF 160 may notify thePCF 135 (that has previously subscribed) with the allocated UE 100 IPaddress/prefix.

In an example, the PCF 135 may provide updated policies to the SMF 160.The PCF 135 may provide authorized session-AMBR and the authorized 5QIand ARP to the SMF 160.

In an example, if request type indicates initial request, the SMF 160may initiate an N4 session establishment procedure 1255 with theselected UPF 110. The SMF 160 may initiate an N4 session modificationprocedure with the selected UPF 110. In an example, the SMF 160 may sendan N4 session establishment/modification request 1255 to the UPF 110 andmay provide packet detection, enforcement, reporting rules, and/or thelike to be installed on the UPF 110 for this PDU session. If CN tunnelinfo is allocated by the SMF 160, the CN tunnel info may be provided tothe UPF 110. If the selective user plane deactivation is required forthis PDU session, the SMF 160 may determine the Inactivity Timer and mayprovide it to the UPF 110. In an example, the UPF 110 may acknowledgesby sending an N4 session establishment/modification response 1255. If CNtunnel info is allocated by the UPF, the CN tunnel info may be providedto SMF 160. In an example, if multiple UPFs are selected for the PDUsession, the SMF 160 may initiate N4 session establishment/modificationprocedure 1255 with each UPF 110 of the PDU session.

In an example, the SMF 160 may send to the AMF 155 anNamf_Communication_N1N2MessageTransfer 1305 message (comprising PDUsession ID, access type, N2 SM information (PDU session ID, QFI(s), QoSprofile(s), CN tunnel info, S-NSSAI, session-AMBR, PDU session type,and/or the like), N1 SM container (PDU session establishment accept (QoSRule(s), selected SSC mode, S-NSSAI, allocated IPv4 address, interfaceidentifier, session-AMBR, selected PDU session type, and/or the like))).In case of multiple UPFs are used for the PDU session, the CN tunnelinfo may comprise tunnel information related with the UPF 110 thatterminates N3. In an example, the N2 SM information may carryinformation that the AMF 155 may forward to the (R)AN 105 (e.g., the CNtunnel info corresponding to the core network address of the N3 tunnelcorresponding to the PDU session, one or multiple QoS profiles and thecorresponding QFIs may be provided to the (R)AN 105, the PDU session IDmay be used by AN signaling with the UE 100 to indicate to the UE 100the association between AN resources and a PDU session for the UE 100,and/or the like). In an example, a PDU session may be associated to anS-NSSAI and a DNN. In an example, the N1 SM container may contain thePDU session establishment accept that the AMF 155 may provide to the UE100. In an example, multiple QoS rules and QoS profiles may be includedin the PDU session establishment accept within the N1 SM and in the N2SM information. In an example, theNamf_Communication_N1N2MessageTransfer 1305 may further comprise the PDUsession ID and information allowing the AMF 155 to know which accesstowards the UE 100 to use.

In an example, the AMF 155 may send to the (R)AN 105 an N2 PDU sessionrequest 1310 (comprising N2 SM information, NAS message (PDU session ID,N1 SM container (PDU session establishment accept, and/or the like))).In an example, the AMF 155 may send the NAS message 1310 that maycomprise PDU session ID and PDU session establishment accept targeted tothe UE 100 and the N2 SM information received from the SMF 160 withinthe N2 PDU session request 1310 to the (R)AN 105.

In an example, the (R)AN 105 may issue AN specific signaling exchange1315 with the UE 100 that may be related with the information receivedfrom SMF 160. In an example, in case of a 3GPP RAN 105, an RRCconnection reconfiguration procedure may take place with the UE 100 toestablish the necessary RAN 105 resources related to the QoS Rules forthe PDU session request 1310. In an example, (R)AN 105 may allocate(R)AN 105 N3 tunnel information for the PDU session. In case of dualconnectivity, the master RAN 105 node may assign some (zero or more)QFIs to be setup to a master RAN 105 node and others to the secondaryRAN 105 node. The AN tunnel info may comprise a tunnel endpoint for eachinvolved RAN 105 node, and the QFIs assigned to each tunnel endpoint. AQFI may be assigned to either the master RAN 105 node or the secondaryRAN 105 node. In an example, (R)AN 105 may forward the NAS message 1310(PDU session ID, N1 SM container (PDU session establishment accept)) tothe UE 100. The (R)AN 105 may provide the NAS message to the UE 100 ifthe necessary RAN 105 resources are established and the allocation of(R)AN 105 tunnel information are successful.

In an example, the N2 PDU session response 1320 may comprise a PDUsession ID, cause, N2 SM information (PDU session ID, AN tunnel info,list of accepted/rejected QFI(s)), and/or the like. In an example, theAN tunnel info may correspond to the access network address of the N3tunnel corresponding to the PDU session.

In an example, the AMF 155 may forward the N2 SM information receivedfrom (R)AN 105 to the SMF 160 via a Nsmf_PDUSession_UpdateSMContextrequest 1330 (comprising: N2 SM information, request type, and/or thelike). In an example, if the list of rejected QFI(s) is included in N2SM information, the SMF 160 may release the rejected QFI(s) associatedQoS profiles.

In an example, the SMF 160 may initiate an N4 session modificationprocedure 1335 with the UPF 110. The SMF 160 may provide AN tunnel infoto the UPF 110 as well as the corresponding forwarding rules. In anexample, the UPF 110 may provide an N4 session modification response1335 to the SMF 160160.

In an example, the SMF 160 may send to the AMF 155 aNsmf_PDUSession_UpdateSMContext response 1340 (Cause). In an example,the SMF 160 may subscribe to the UE 100 mobility event notification fromthe AMF 155 (e.g. location reporting, UE 100 moving into or out of areaof interest), after this step by invoking Namf_EventExposure_Subscribeservice operation. For LADN, the SMF 160 may subscribe to the UE 100moving into or out of LADN service area event notification by providingthe LADN DNN as an indicator for the area of interest. The AMF 155 mayforward relevant events subscribed by the SMF 160.

In an example, the SMF 160 may send to the AMF 155, aNsmf_PDUSession_SMContextStatusNotify (release) 1345. In an example, ifduring the procedure, any time the PDU session establishment is notsuccessful, the SMF 160 may inform the AMF 155 by invokingNsmf_PDUSession_SMContextStatusNotify(release) 1345. The SMF 160 mayreleases any N4 session(s) created, any PDU session address if allocated(e.g. IP address) and may release the association with the PCF 135.

In an example, in case of PDU type IPv6, the SMF 160 may generate anIPv6 Router Advertisement 1350 and may send it to the UE 100 via N4 andthe UPF 110.

In an example, if the PDU session may not be established, the SMF 160may unsubscribe 1360 to the modifications of session managementsubscription data for the corresponding (SUPI, DNN, S-NSSAI), usingNudm_SDM_Unsubscribe (SUPI, DNN, S-NSSAI), if the SMF 160 is no morehandling a PDU session of the UE 100 for this (DNN, S-NSSAI). In anexample, if the PDU session may not be established, the SMF 160 mayderegister 1360 for the given PDU session using Nudm_UECM_Deregistration(SUPI, DNN, PDU session ID).

FIG. 14 depicts an example architecture of a 5G communication system asper an aspect of an embodiment of the present disclosure. The 5G systemcomprises a 5G Core Network (5GC) and a Next Generation Radio AccessNetwork (NG-RAN). The NG-RAN may be a base station of 5G system and maycomprise a gNB, an ng-eNB and/or the like. The gNB may provide new radio(NR) user plane and control plane protocol that terminates towards awireless device (e.g. UE). The ng-eNB may provide Evolved UniversalTerrestrial Radio Access (E-UTRA) user plane and control plane protocolterminations towards the wireless device. The gNBs and ng-eNBs may beinterconnected with each other via one or more Xn interfaces. The gNBsand ng-eNBs may be also connected to the 5GC via one or more NGinterfaces (e.g. to an AMF via an NG-C interface and/or to a UPF via anNG-U interface).

A satellite may be a space-borne vehicle embarking a bent pipe payloador a regenerative payload telecommunication transmitter. The satellitemay be placed into a low-earth orbit (LEO) at an altitude between 300 kmto 1500 km, a medium-earth orbit (MEO) at an altitude between 8000 to20000 km, or a geostationary satellite earth orbit (GEO) at 35,786 kmaltitude. A satellite network may be a network or network segment thatuses a space-borne vehicle to embark a transmission equipment relay nodeor a base station. While a terrestrial network is a network located onthe surface of the earth, a non-terrestrial network (NTN) may be anetwork which uses a satellite as an access network, a backhaulinterface network, or both.

FIGS. 15A and 15B are examples of NTN architectures in which a satelliteis used as part of a network as per embodiments of the presentdisclosure.

FIG. 15A shows an example NTN architecture corresponding to atransparent satellite model. The NTN architecture of FIG. 15A comprisesa wireless device, a satellite, an NTN gateway, a base station, a 5Gcore network, and a data network. In the NTN architecture of FIG. 15A,the satellite may behave as a remote radio unit (RRU) communicating withthe NTN gateway. The NTN gateway may connect to a base station on theground. The wireless device may transmit and receive via the satelliteand the satellite may implement frequency conversion and radio frequencyamplification in both the uplink and downlink directions. The satellite(an RRU in this example) may correspond to an analogue RF repeater thatrepeats the NR-Uu radio interface from a service link (between thesatellite and the wireless device) to a feeder link (between the NTNgateway and the satellite), and vice-versa.

FIG. 15B shows an example NTN architecture regarding corresponding to aregenerative satellite model. The NTN architecture of FIG. 15B comprisesa wireless device, a satellite, an NTN gateway, a 5G core network,and/or the like. The satellite may regenerate signals received fromearth (e.g. from a wireless device or from an NTN gateway). In anexample, the satellite may behave as a base station.

FIG. 16 depicts an example wireless network architecture in which asatellite is used as part of a backhaul interface as per embodiments ofthe disclosure. The NTN architecture of FIG. 16 comprises a wirelessdevice, an access network/base station, a satellite, a 5G core network,and a data network. In the example of FIG. 16 , the access network/basestation is a terrestrial access network which is located on a surface ofthe earth. However, it will be understood that the access network mayalso have an NTN architecture analogous to the NTN architectures shownin, for example, FIGS. 15A and/or 15B. As shown in the example of FIG.16 , the 5G core network may also be located on a surface of the earth.The wireless device may communicate with the access network/basestation. The access network/base station may communicate with the 5Gcore network via a satellite radio interface (e.g., a satellitebackhaul). The satellite radio interface may provide a transport fornext generation (NG) reference points (e.g. N2/N3) between theterrestrial access network and the 5G core network. In an example, thesatellite may transparently carry the communication payload of the NGreference points.

FIG. 17 depicts earth orbits of example satellites. In an example, a lowearth orbit (LEO) orbits earth with an altitude ranging from 300 km to1500 km above the surface of the earth. An orbital period of the LEO maybe between about 84 minutes and 127 minutes. In an example, mean orbitalvelocity needed to maintain a stable LEO may be 7.8 km/s and may bereduced with increased orbital altitude. In an example, mean orbitalvelocity for circular orbit of 200 km may be 7.79 km/s. In an example,mean orbital velocity for circular orbit 1500 km may be 7.12 km/s. Inanother example, a geostationary satellite earth orbit (GEO) orbitsearth with an altitude 35,786 km above the surface of the earth. The GEOmay be established at an altitude very close to 35,786 km (22,236 mi)and directly above the equator. This equates to an orbital velocity of3.07 km/s (1.91 mi/s) and an orbital period of 1,436 minutes, whichequates to almost one sidereal day (23.934461223 hours). From theperspective of a given point on the surface of the earth, the positionof the LEO satellite may change, while the position of the GEO may notmove.

FIG. 18 shows different types of non-terrestrial networks comprising lowearth orbiting (LEO) satellites, medium earth orbiting (MEO) satellites,geostationary earth orbiting (GEO), unmanned aircraft system (UAS) andhighly elliptical orbiting (HEO) satellites. In an example, the typicalbeam footprint size of the GEO satellite is 200˜1000 km. The footprintof a communications satellite may be the ground area that itstransponders offer coverage and determines the satellite dish diameterrequired to receive each transponder's signal. The transponders may be awireless device.

Propagation delay may be the amount of time it takes for the head of thesignal to travel from a sender to a receiver or vice versa. For uplink,the sender may be a wireless device and the receiver may be a basestation/access network. For downlink, the sender may be a basestation/access network and the receiver may be a wireless device. Thepropagation delay may vary depending on a distance between the senderand the receiver.

FIG. 19 shows examples of propagation delay corresponding to NTNs ofdifferent altitudes. The propagation delay of this example figure isone-way latency. In an example, one-way latency is an amount of timerequired to propagate through a telecommunication system from a terminalto the receiver (e.g. base station, eNB, gNB, RRU of a base station). Inan example, for the transparent satellite model of GEO case, theround-trip propagation delay including service link (e.g. between thesatellite and the wireless device) and feeder link (e.g. between the NTNgateway and the satellite) may be four times of 138.9 milliseconds(approximately 556 milliseconds). If processing time and congestion aretaken into account, the round-trip delay of the GEO satellite may bemore than a few seconds. In an example, terrestrial network (e.g. NR,E-UTRA, LTE) round-trip propagation delay may negligible. In an example,terrestrial network round-trip propagation delay may be less than 1millisecond. In an example, the GEO satellite round-trip delay may behundreds of times longer than the one of terrestrial network.

FIG. 20 is an example architecture of a 5G system having a 5G corenetwork that provides service to different types of access networks asper an aspect of an embodiment of the present disclosure. As shown inFIG. 20 , the different types of access networks may include terrestrialaccess networks and non-terrestrial access networks. An ng-eNB mayconstitute a type of terrestrial access network and a gNB may constituteanother type of terrestrial access network. A non-GEO (e.g. LEO)satellite may a type of non-terrestrial access network and a GEOsatellite may constitute another type of non-terrestrial access network.The 5G core network may operate multiple access networks which havedifferent physical perspectives (e.g. latency, throughput, delay).

FIG. 21 depicts an architecture (left side) and coverage map (rightside) of a deployment scenario in which one public land mobile network(e.g. PLMN A) provides both a non-terrestrial access network and aterrestrial access network. In an example, a wireless device may be ableto access the non-terrestrial access network and the terrestrial accessnetwork. In this deployment scenario, separate NG instances (e.g. N2,N3) are handling separate access type nodes. The coverage of thenon-terrestrial access network may span over the coverage of theterrestrial access network. In an example, the PLMN A is a Verizon, AT&Tand/or the like. In an example, Verizon may deploy a cellular accessnetwork (e.g. 4G, 5G terrestrial network) and a non-terrestrial accessnetwork. A wireless device which is a subscriber of Verizon may accessto a core network via the terrestrial access network when the wirelessdevice is in a coverage area of the terrestrial access network. In anexample, urban area or suburban area may be the coverage area of theterrestrial access network. The wireless device may access the corenetwork via the non-terrestrial access network when the wireless deviceis out of coverage area of the terrestrial access network. In anexample, the rural area or mountain area may be out of the terrestrialaccess network coverage.

FIG. 22 depicts an architecture (left side) and coverage map (rightside) of a scenario in which two different public land mobile networks(e.g. PLMN A and PLMN B) respectively provide a non-terrestrial accessnetwork and a terrestrial access network. In an example, the PLMN B is aVerizon, AT&T and/or the like. In an example, the PLMN B is an Iridiumcommunication. In an example, Verizon may have roaming agreement withnon-terrestrial network operator Iridium communication. A wirelessdevice which is subscriber of the Verizon may access Verizon terrestrialaccess network if the wireless device resides in the coverage of theterrestrial access network. The wireless device may roam to thenon-terrestrial access network, PLMN B, if the wireless device is out ofcoverage of the terrestrial access network.

FIG. 23 depicts an example control plane protocol stack between awireless device and various network functions (e.g. AMF, SMF). In anexample, the wireless device is a user equipment (UE). In an example,the wireless device is a transponder. As shown in FIG. 23 , a non-accessstratum (NAS) procedure may be used by protocols for mobility managementand session management between a UE and the network functions (e.g. AMF,SMF, PCF). Mobility management (MM) may be between a user equipment (UE)and the access and mobility management function (AMF) for both 3GPPaccess (e.g. LTE, New Radio, 3G, 4G, 5G) and non-3GPP access (e.g. IEEEdefined radio access). Session management (SM) may be between the userequipment (UE) and the session management function (SMF) for both 3GPPaccess and non-3GPP access. In an example, NAS-MM is protocol interfacebetween the UE and the AMF. In an example, NAS-SM is protocol interfacebetween the UE and the SMF. The main function of the mobility management(5GMM) sublayer is to support the identification, security, mobility ofa UE as well as generic message transport. The main function of the 5GSMsublayer is to support the packet data unit (PDU) session handling inthe UE and in the SMF (transferred via the AMF). The 5GSM may comprisesprocedure for an authentication and authorization, establishment,modification and release of PDU sessions.

The UE (wireless device) and the network functions may maintain andcontrol non-access stratum (NAS) timers for each NAS procedure in orderto handle abnormal cases and proper operations. There may be multiplecategories of timers, for example, NAS timers for mobility managementand NAS timers for session management. In an example, the UE may start aNAS timer when the UE starts a NAS procedure (e.g. registrationprocedure, service request procedure). In an example, the UE may startthe NAS timer in response to sending a NAS request message to a networkfunction (e.g. AMF, SMF, PCF). If the UE does not receive a NAS responsemessage corresponding to the NAS request message from the networkfunction before an expiration of the NAS timer (before timeout of theNAS period), the UE aborts the ongoing NAS procedure. The UE may alsodetermine to retransmit (re-send) the NAS request message after a pause.A period of the pause may be determined by another NAS timer. In anexample, a wireless device may determine a retransmission (re-sending)of the NAS request message based on the expiration of the NAS timer.

FIGS. 24 and 25 illustrate usage of NAS timers in the context of aregistration procedure, in which a UE sends a registration requestmessage for mobility and periodic registration to an AMF via an accessnetwork. FIG. 24 illustrates a successful case in which the UE receivesa response message from an AMF before a timeout (expiration) of the NAStimer. FIG. 25 is a case in which the UE does not receive a responsemessage.

FIG. 24 illustrates a registration procedure in which a UE attempts toregister with an AMF. In a first scenario, shown at the top of FIG. 24 ,the UE sends a registration request message to the AMF requesting aregistration of the UE. The registration request message may comprise aregistration type, a UE identity (e.g., SUCI, 5G-GUTI), the location ofthe UE (e.g., last visited TAI), requested NSSAI, UE mobility managementcontext information, information for the MICO mode usage, and/or thelike. In an example, the registration type may indicate a mobility orperiodic registration. The UE may start a first NAS timer referred to asUE NAS timer A. The UE NAS timer A illustrated in FIG. 24 maycorrespond, for example, to the timer T3510 identified in 3GPPstandards. The UE NAS timer A may be started simultaneously with or inresponse to the sending of the registration request message. The accessstratum layer of the UE may perform a random-access procedure toestablish a radio resource control (RRC) connection setup with an accessnetwork. If the AMF receives the registration request messagesuccessfully (as it does in FIG. 24 ), the AMF may send a registrationaccept message to the UE. In an example, the registration accept messagemay comprise 5G-GUTI, registration area, a periodic registration areaupdate time value, a MICO mode indication, and/or the like.

If the registration accept message includes a temporary identity (e.g.,5G-GUTI), the AMF may start a timer simultaneous with or in response tothe sending of the registration accept message. This timer may bereferred to as AMF NAS timer A, and may correspond to the timer T3550identified in the 3GPP standards. The UE may stop the UE NAS timer A inresponse to receiving the registration accept message is receivedsuccessfully from the AMF (as shown in FIG. 24 ). If the registrationaccept message comprising a temporary identity (e.g. 5G-GUTI), the UEmay send a registration complete message to the AMF. The AMF may stopthe AMF NAS timer A in response to receiving the registration completemessage from the UE.

In a second scenario, shown at the bottom of FIG. 24 , the AMF mayreject the registration procedure by sending a registration rejectmessage to the UE. The AMF may reject the registration if, for example,there is congestion when the registration request message is received.The UE may stop the UE NAS timer A in response to receiving theregistration request message. The subsequent behavior of the UE may bebased on a cause value in the registration reject message.

FIG. 25 illustrates another registration procedure in which a UEattempts to register with an AMF. In FIG. 25 , the UE may send aregistration request message analogous to the registration requestmessage shown in FIG. 24 . The UE may also start the UE NAS timer A. Inan example, the period of the UE NAS timer A may be 15 seconds. In thescenario of FIG. 25 , the NAS timer expires while the UE is waiting foran NAS response message (e.g. registration accept, registration reject).Simultaneous with or in response to the expiration of the UE NAS timerA, the UE starts a second NAS timer, referred to in the present exampleas UE NAS timer B. If the UE NAS timer B, expires, the UE may increase aregistration attempt counter and may re-send (retransmit) theregistration request message and restart the UE NAS timer A. If aregistration accept message is received in response to theretransmission of the request (as shown in FIG. 25 ), then the UE NAStimer A stops. If no registration accept message is received and theregistration attempt counter reaches or exceeds a predefined value(e.g., 5), the UE may abort the ongoing procedure (not shown in FIG. 25).

In an example, a NAS procedure such as service request procedure, oneNAS timer (e.g. first NAS timer) may be used to abort the NAS procedure.In an example, retransmission of the same NAS request message may nothappen for the service request procedure based on an expiration of thefirst NAS timer. The UE may abort the service request procedure inresponse to the expiration of the first NAS timer. A UE may send anotherservice request message in response to upper layer request. In anexample, a service request for service A is aborted in response to anexpiration of a first NAS timer. The wireless may send a service requestmessage in response to a connection request for service B from an upperlayer of the UE. In an example, the upper layer of a UE may beapplication layer of the UE.

In existing wireless technologies (e.g. 5G system), non-access stratum(NAS) handling may be access agnostic, for example, when an AMF supportsmultiple access technologies. In an example, a wireless device mayaccess a 5G core (e.g. AMF) via a base station employing NR (gNB). Thewireless device may access a 5G core (e.g. AMF) via a base stationemploying E-UTRA (ng-eNB). Irrespective of accessing via the NR or theE-UTRA, the wireless device may adopt the same NAS timings (e.g., theperiods/values of one or more NAS timers). In an example, a wirelessdevice may start a NAS procedure (e.g., registration procedure, servicerequest, and/or the like) by sending a NAS request message (e.g.,registration request message, service request message, and/or the like)to an AMF. The wireless device may start a first NAS period (e.g.,corresponding to UE NAS timer A) when sending the NAS request message.The first NAS period may correspond to a preconfigured value (e.g., 15seconds). The wireless device may determine that the NAS procedure hasfailed if the wireless device does not receive a NAS response messageprior to an expiration of the first NAS period. In an example, thewireless device may abort the NAS procedure (e.g. service requestprocedure) in response to the expiration of the first NAS period. In anexample, the wireless device may abort the NAS procedure (e.g.registration procedure) and start a second NAS period (e.g.,corresponding to UE NAS timer B) when the first NAS period expires. Thesecond NAS period may be, for example, 10 seconds. The wireless devicemay send a second NAS request message when the second NAS period expiresand may abort the NAS procedure after a number of failed attempts.

Configuration of NAS timers in existing technologies may result in highsignaling overhead and excessive connection failure when multiple accesstechnologies are implemented in a wireless device. For example, whendifferent access technologies such as GEO type access network, LEO typeaccess network, and/or terrestrial access network are implemented in a5G network, the wireless device may experience increased connectionfailures because of expiry of NAS timers. For example, incomplete NASregistration procedures may result in increased connections failureswhen the wireless device connect to the 5G network. If existing NAStimers configurations are used, then a wireless device accessing an AMFvia a non-terrestrial networks (NTN) may re-send a NAS message or abortthe NAS procedure. Implementation of existing technologies may increasesignaling overhead even though the AMF respond to the NAS registrationprocedure promptly. The wireless device may abort the NAS procedure,which causes a delay for a connection setup. Example embodimentsenhances NAS timer configurations to reduce connections failures duringthe access procedures. Example embodiment takes into account relativelylonger propagation delays non-terrestrial networks (NTN) to enhance NAStimer configuration. Example embodiments implement enhanced timermanagement processes for NAS procedures to reduce connection failure andsignaling overhead. The enhanced timer management processes of thepresent disclosure may accommodate a wider variety of access types. Theexample embodiments may reduce expiry of a NAS timer before receivingthe registration accept message and allow reasonably long delay for aresponse to arrive.

In example embodiment, one or more public land mobile network (e.g. PLMNA) may employ non-terrestrial network (NTN), terrestrial network, orboth. In an example, as depicted in FIG. 15A and FIG. 15B, the PLMN mayemploy the NTN for a Uu interface between a wireless device and anaccess network (e.g. base station, gNB). As depicted in FIG. 16 , thePLMN may employ the NTN for backhaul interface (e.g. NG interface, N2/N3interface) between an access network (e.g. base station, gNB) and 5Gcore network (e.g. AMF, UPF). In yet other scenarios the PLMN may employan NTN in both the access network and the backhaul. Employing the NTN asthe Uu interface or the NG interface may result in longer propagationdelay compared to terrestrial network. In an example, a propagationdelay of the terrestrial network (e.g. gNB (NR), ng-eNB(E-UTRA)) may benegligible. In an example, a round-trip propagation delay of terrestrialnetwork may be under a 1 microsecond. In an example, a round-trippropagation delay of NTN may be from tens of times (for LEO) to hundredsof times (for GEO) comparing to a terrestrial network. In an example,the round-trip propagation delay of LEO may be negligible, and theround-trip propagation delay of GEO may not be negligible.

In an example embodiment, a wireless device (e.g., UE) may access a PLMNvia an access network. The wireless device may determine NAS periods/NAStimers (e.g. first NAS period, second NAS period, third NAS period)based on access network information received from an access network ofthe PLMN. The access network information may indicate an access networktype of a plurality of access network types. For example, the pluralityof access network types may comprise a non-terrestrial network (NTN), aterrestrial network (TN), and/or the like. The NTN access network typemay comprise a GEO NTN access network type, a LEO NTN access networktype, a MEO NTN access network, and/or the like. In an example, the NASperiods/NAS timers may be equal to a first set of values based on theaccess network information indicating the GEO access network type. TheNAS periods/NAS timers may be equal to a second set of values based onthe access network information indicating the LEO TN. The first set ofvalues may be longer than the second set of values. In an example, theNAS periods/NAS timers may be equal to the second set of values based onthe access network information indicating the TN access network type. Inan example, the NAS periods/NAS timers may be longer when the accessnetwork information includes NTN than when the access network includesTN (does not include the NTN). In an example, the first set of valuesfor the NAS periods/NAS timers may be longer than the second set forvalues for the NAS periods/NAS timers a few hundred seconds (e.g. 200s,300s).

The wireless device may receive a backhaul network information from thePLMN (e.g., AMF, access network/base station, and/or the like). Thewireless device may update/re-determine the NAS periods/NAS timers basedon the backhaul network information in response to receiving thebackhaul network information from the PLMN. In an example, the NASperiods/NAS timers may be extended with a delta value (e.g. 100 seconds)in response to the backhaul network information indicating the NTN. Inan example, the NAS periods/NAS timers may be not changed in response tothe backhaul network information indicating the TN. Determining the NASperiods/NAS timers (first NAS period, second NAS period, third NASperiod) based on the access network information/type and/or the backhaulnetwork information, may reduce signaling overload and improve userexperience.

FIG. 26 illustrates an example embodiment of a present disclosurecomprising a wireless device (e.g. a UE), an access network/basestation, and an AMF. In an example, a wireless device may handle one NASperiod/timer to determine a re-transmission (re-sending) of the NASrequest message. The wireless device may receive, from the accessnetwork/base station, access network information indicating an accessnetwork type. The access network information may be included in systeminformation block. In an example implementation, the wireless device maydetermine the access network type based on a detected numerology (e.g.modulation scheme, frequency band, and/or the like) of the accessnetwork. The access network type may comprise a terrestrial network(TN), a non-terrestrial network (NTN) and/or the like. The NTN maycomprise a low earth orbit (LEO) satellite type, a medium earth orbit(MEO) satellite type, a geostationary earth orbit (GEO) satellite type,an unmanned aircraft system (UAS) platform type, a high elliptical orbit(HEO) platform type, and/or the like. In an example implementation, theTN may comprise a narrow band internet of things type, an enhancedmachine type communication (MTC) type, a wide-band evolved terrestrialradio access (WB-E-UTRA) type, a new radio (NR)type, and/or the like. Inan example implementation, the TN may comprise a wide-band evolvedterrestrial radio access (WB-E-UTRA) type, a new radio (NR)type, and/orthe like. The wireless device may determine a first NAS period (e.g., afirst NAS timer, a period value for the first NAS timer) based on theaccess network type in response to receiving/detecting the accessnetwork information/type.

In an example, the first NAS period/NAS timer may be equal to a firstvalue based on the access network information indicating the NTN. Thefirst NAS period/NAS timer may be equal to a second value based on theaccess network information indicating the TN. The first value may bedifferent from the second value. The first value may be longer than thesecond value. In an example, the first value may be 215 seconds and thesecond value may be 15 seconds.

In an example implementation, the NTN may comprise a GEO, and the firstvalue may be longer than the second value. In another exampleimplementation, the NTN may comprise a LEO, and the first value may belonger than the second value, but not as long as the first valueassociated with the GEO. In yet another example implementation, the NTNmay comprise a LEO, and the first value may be the same as the secondvalue.

In an example implementation, a third value or fourth value may beexisted to support more granularity timer handling.

In an example implementation, the first value and/or the second valuemay be pre-configured in the wireless device. In another exampleimplementation, the access network information may indicate the firstvalue and/or the second value. In yet another example implementation,the access network information may indicate an access type, from whichthe first value and/or the second value may be inferred.

In an example, the wireless device may initiate a NAS procedure bysending a first NAS request message to the AMF. The wireless device maystart the first NAS period in response to sending the first NAS requestmessage. If the wireless device does not receive a first NAS responsemessage from the network (e.g., AMF) prior to an expiration of the firstNAS period/timer, the wireless device may abort/stop the NAS procedure.In an example implementation, the wireless device may send a second NASprocedure in response to the expiration of the first NAS period/timer.The wireless device may increment an NAS attempt counter by 1 inresponse to the expiration of the first NAS period. The NAS attemptcounter may be used to limit the number of NAS request attempts whenthere is no response form the network (e.g. AMF). If the NAS attemptcounter is greater or equal to NAS attempt maximum counter value, thewireless device may start a third NAS period/timer. In an example, theNAS attempt maximum counter may be 5. In an example, the third NASperiod/timer may be T3525 in response to the NAS procedure being aservice request procedure. In an example, the wireless device may sendthe NAS request message after the third NAS period/timer is expired.

FIG. 27 illustrates an example embodiment of a present disclosurecomprising a wireless device (e.g. UE) and an access network/basestation. The wireless device may determine an operating mode based onthe received access network information/type via system informationblock. In an example implementation, the wireless device maydetermine/detect a numerology (e.g. modulation scheme, frequency band,and/or the like) of the access network. The wireless device maydetermine the first NAS period/timer (e.g., NAS periods/timers) based onthe operating mode. In an example, the operating mode may comprise aterrestrial operation mode, a wide band terrestrial operation mode, anarrow band terrestrial operation mode, a non-terrestrial operationmode, a non-terrestrial low earth orbit (LEO) operation mode, anon-terrestrial medium earth orbit (MEP) operation mode, anon-terrestrial geostationary earth orbit (GEO) operation mode, anon-terrestrial unmanned aircraft system (UAS) operation mode, and/orthe like. In an example, the wireless device may determine the operatingmode as the non-terrestrial geostationary earth orbit (GEO) operationmode in response to the access network being a GEO. In an example, thewireless device may determine the operating mode as the wide bandterrestrial operation mode in response to the access network being NR orE-UTRA. In an example, the wideband terrestrial operation mode may be S1mode.

FIG. 28 illustrates an example wherein a wireless device receives aresponse message from the network (e.g., AMF/SMF). As described in FIG.26 , the wireless device (e.g., UE) may determine a first NASperiod/timer based on the access network information/type. The wirelessdevice may initiate by sending a first NAS request message to thenetwork. The network (e.g., AMF) may send a first NAS response messagein response to receiving the first NAS request message. If the wirelessdevice receives the first NAS response message prior to an expiration ofthe first NAS period/timer (as it does in the example of FIG. 28 ), thewireless device may stop the first NAS period/timer. If a NAS attemptcounter is not zero, the wireless device may reset (set as zero) the NASattempt counter in response to receiving the first NAS response message.

In an example implementation, the wireless device may receive backhaulnetwork information of the core network from the network. The first NASresponse message may comprise the backhaul network information. Thebackhaul network information may comprise NTN type information, backhaullatency information, altitude information, and/or the like.

The wireless device may determine a second NAS period/timer based on thebackhaul network information. The wireless device may adapt the NAStimings based on the backhaul network information. For example, thewireless device may determine a second NAS period/timer based on thefirst NAS period and the backhaul network information. In an example,the second NAS period may be equal to the sum of the first NAS periodand a delta value. The delta value may vary based on whether or not thebackhaul includes an NTN. For example, the delta value may be aparticular size based on the backhaul network information indicating theNTN (or indicating a particular type of NTN), and may be a smaller sizeor zero based on the backhaul network information indicating no NTN (orindicating a different type of NTN). In an example, the second NASperiod is equal to the first NAS period, based on the backhaul networkinformation indicating the TN. In an example, the delta value may bepre-configured in the wireless device. In an example, the delta valuemay be broadcasted by the access network. In an example, the backhaulnetwork information may comprise the delta value. The wireless devicemay initiate a NAS procedure by sending a third NAS request message. Thefirst NAS request message may be same NAS message with the third NASrequest message. The wireless device may start the second NASperiod/timer in response to the sending the third NAS request message.The wireless device may use the same physical/logical NAS timer (e.g.T3510, T3517) for the first NAS period and the second NAS period. Theduration of the second NAS period may differ from the duration of thefirst NAS period based on the backhaul network information.

In an example implementation, it may be efficient to inform a wirelessdevice of possible backhaul network information (e.g., possible backhaulinterface propagation delay/latency) prior to receiving a first NASresponse message. The wireless device may determine the first NAS timerbased on an access network information and the backhaul networkinformation at the initial access/procedure as below.

FIG. 29A and FIG. 29B illustrate example embodiments of a latencyrelated information exchange. FIG. 29A illustrates, for example, a firstNGAP procedure triggered after the TNL (transport network layer)association has become operational. The base station may initiate theprocedure by sending an NG setup request message to the AMF. The NGsetup request message may comprise an identity of the base station, adefault paging discontinuous reception (DRX) cycle, supported trackingareas list with supported slice info, non-terrestrial networkinformation, latency information, and/or the like. In an example, thenon-terrestrial network information may comprise an employed satellitetype (e.g. LEO, MEO, GEO and/or the like). In an example, the latencyinformation may comprise a time value, altitude information and/or thelike. The AMF may send a NG setup request response message to the basestation in response to receiving the NG setup request message. The NGsetup request response message may comprise an AMF name, a servedglobally unique AMF identifier (GUAMI) list, a PLMN support list,backhaul network information and/or the like. The PLMN support list maycomprise a PLMN identity and supported S-NSSAIs per tracking area. In anexample, the backhaul network information may comprise backhaul latencyinformation, non-terrestrial network type information, and/or the like.The backhaul latency information may comprise actual latency as a timevalue (e.g. 30 milliseconds, 1 second, 2 seconds, 3 seconds, 100seconds, 200 seconds and/or the like). In an example, thenon-terrestrial network (NTN) type information may comprise an employedsatellite network type or altitude information and/or the like. In anexample, the employed satellite network type may comprise a LEO, MEO,GEO and/or the like. In an example, the altitude information maycomprise the altitude of the backhaul satellite. In an example, thealtitude of the backhaul satellite may comprise 300 km, 400 km, 500 km,100 km, 1500 km, 2000 km, 3000 km and/or the like. In an example, thealtitude of the backhaul satellite may be preconfigured indexinformation.

FIG. 29B illustrates, for example, an update to application levelconfiguration data needed for the base station (NG-RAN) and the AMF tointeroperate correctly on the NG-C interface. The base station may senda RAN configuration update message to the AMF. The RAN configurationupdate message may comprise an identity of the base station, a defaultpaging discontinuous reception (DRX) cycle, supported tracking areaslist with supported slice info, the non-terrestrial network information,the latency information, and/or the like. The AMF may send a RANconfiguration update acknowledge message to the base station in responseto receiving the RAN configuration update message. In an example, theRAN configuration update acknowledge message may comprise an AMF name, aserved globally unique AMF identifier (GUAMI) list, a PLMN support list,backhaul network information and/or the like.

In an example, the propagation delay or latency of delivery of packetbetween in Uu interface/radio interface (from a wireless device to anaccess network/base station) may degrade user service experience. In anexample, the high latency due to propagation delay may not appropriatefor some user services (e.g. a critical service, an interactiveservice). In an example, as explained in 29A, 29B, the accessnetwork/base station may send a latency related information to corenetwork. The core network (e.g. AMF, SMF) may determine acceptable QoSservice based on the latency related information. In an example, thecore network may provide the latency related information to a PCF. ThePCF may determine an acceptance of any requested service QoS based onthe latency related information. In an example, the latency relatedinformation may comprise a non-terrestrial information or a latencyinformation (e.g. delivery time) if the access network includes anon-terrestrial network.

In an example, the propagation delay or latency of delivery of packetbetween in backhaul interface/NG interface (from an access network/basestation to core networks) may degrade user service experience. In anexample, the high latency due to propagation delay may not appropriatefor some user services (e.g. a critical service, an interactiveservice). In an example, the access network may adapt/determineparameters (e.g. QoS, RRC timers, throughput, and/or the like) based onthe backhaul latency. The core network (e.g. AMF) may send a latencyrelated information of the backhaul to the access network. In anexample, the latency related information may comprise a non-terrestrialinformation or a latency information (e.g. delivery time) of thebackhaul if the core network interface includes a non-terrestrialnetwork.

In an example implementation, an access network may indicate apropagation delay/backhaul latency of a core network (backhaulinterface) to a wireless device via broadcasting (system informationblock) to a wireless device. The propagation delay/backhaul latency ofthe core network may be a potential one if the access network isconnected multiple core networks. The access network may broadcast thepropagation delay/backhaul latency as a common information elementwithout distinction between different core networks. In an example, theaccess network may be connected to multiple core networks. In anexample, the access network may be connected to two core networks (e.g.core network A, core network B). A backhaul interface with the corenetwork A may be a terrestrial network type and a backhaul interfacewith the core network B may be a non-terrestrial network (NTN) type. Inan example, the access network may exchange with the core network B thelatency related information of the backhaul as illustrated in FIG. 31Aand FIG. 31B. The access network may broadcast the propagationdelay/backhaul latency without distinction between the core network Aand the core network B. In an example, the access network may broadcastthe propagation delay/backhaul latency with distinction between the corenetwork A and the core network B. If a wireless device accesses the corenetwork A via the access network, the wireless device may determine afirst NAS period/timer without considering the propagationdelay/backhaul latency information. If a wireless device accesses thecore network B via the access network, the wireless device may determinea first NAS period/timer based on the propagation delay/backhaul latencyinformation. The first NAS period for the core network B may be longerthan the first NAS period for the core network A.

In an example implementation, an access network may provide apropagation delay/backhaul latency of a core network (backhaulinterface) to a wireless device via radio resource control (RRC)message. This example implementation may be efficient since the accessnetwork sends the RRC message comprising the propagation delay/backhaullatency information after the access network/base station selects a corenetwork (e.g., core network A or core network B) for routing a first NASrequest message. In an example, the access network/base station selectthe AMF based on S-NSSAI, UE capability information. In an example, ifthe access network selects the core network A (terrestrial type backhaulinterface, low/no latency) for a wireless device, the access network maynot provide the propagation delay/backhaul latency to the wirelessdevice. If the access network selects the core network B(non-terrestrial type backhaul interface, middle/high latency), theaccess network may provide the propagation delay/backhaul latency to thewireless device.

FIG. 30 shows an example flow chart of a present disclosure. In anexample implementation, a wireless device may employ two NAS timers(e.g. T3510, T3511) for NAS request message retransmission if there isno response from a network (e.g. AMF) in a given time (e.g., a timevalue of a NAS timer C). In an example, a registration procedure mayemploy two NAS periods/timers. The wireless device (e.g. UE) may receiveaccess network information and determine a NAS period A (e.g. T3510), aNAS period B (e.g. T3511) and the pause NAS period C (T3502). In anexample, the wireless device may determine the value of NAS periodsbased on access network information. The NAS periods/timers may be equalto a first set of values in response to the access networkinformation/type comprising an NTN. The NAS periods/timers may be equalto a second set of values in response to the access networkinformation/type comprising an TN. In an example implementation, the NASperiods/timers may be equal to a first set of values in response to theaccess network information/type comprising an access network typeimplying longer latency/propagation delay. The NAS periods/timers may beequal to a second set of values in response to the access networkinformation/type comprising access network type implying shorter/normallatency/propagation delay. In an example, the second set of values maybe from a few seconds to tens of seconds (e.g. T3510=15 s, T3511=10 s,T3502=12 minutes). In an example, the first set of values may be a fewhundreds of seconds (e.g. T3510=215 s, T3511=210 s, T3502=1 hours). Inan example, the first set of values may be the sum of the second set ofvalues and a time delta. The time delta (e.g., 200 s, 300 s, 400 s) maybe a hundred of seconds to a few minutes/hours.

The wireless device may initiate a NAS procedure by sending a first NASrequest message. The wireless device may start the NAS period A (T3510)in response to initiate the NAS procedure (sending the first NAS requestmessage). In an example, the wireless device may wait to receive a firstNAS response message from a core network (e.g. AMF, SMF). If thewireless device receives the first NAS response message prior to anexpiration of the NAS period A, the wireless device may stop the NASperiod A. The wireless device may reset an NAS attempt counter to zeroin response to receiving the first NAS response message.

In an example, the wireless device may not receive the first NASresponse message and the NAS period A may be expired. The wirelessdevice may abort the NAS procedure and start the NAS period B (T3511) inresponse to the expiration of the NAS period A. In an example, if thewireless device transitions into CM-CONNECTED state/mode prior to anexpiration of the NAS period B, the wireless device may stop the NASperiod B. If the wireless device does transition into CM-CONNECTEDstate/mode prior to the expiration of the NAS period B, the wirelessdevice may increment the NAS attempt counter by 1. If the NAS attemptcounter is greater or equal to a NAS attempt maximum counter value (e.g.5), the wireless device may start a NAS period C (e.g. T3502). Thewireless device may pause (does not initiate same NAS procedure) the NASprocedure the time duration that the NAS period/timer C is running. Inan example, the wireless device does not initiate the same NASprocedure/NAS procedure prior to an expiration of the NAS period C. Ifthe NAS attempt counter is less than the NAS attempt maximum countervalue, the wireless device may send a second NAS request message. Thesending of the second NAS request message is equal to retransmit/re-sendsame context of the first NAS request message.

FIG. 31 shows an example flow chart of a present disclosure. A wirelessdevice (e.g., UE) may determine operating mode based on received accessnetwork information/type. The wireless device may determine NAS periods(e.g. NAS period A, NAS period B, NAS period C) for each NAS procedure(e.g. registration procedure, service request procedure, PDU sessionestablishment procedure) based on the operating mode and/or the accessnetwork information/type. The wireless device may initiate/trigger a NASprocedure by sending a NAS request message (e.g. registration requestmessage). In an example, the wireless device may receive a NAS responsemessage (e.g. registration access message) prior to an expiration of aNAS period (NAS period A). If the NAS response message comprisingbackhaul network information, the wireless device may re-determine NASperiods/NAS timers for each NAS procedure based on the backhaul networkinformation.

In an example, a wireless device may receive from an access network andthe access network information may indicate an access network type of aplurality of access network types. The access network type may comprisea non-terrestrial network (NTN) access network type, a terrestrialnetwork (TN) access network type.

In an example, the wireless device may determine a first non-accessstratum (NAS) period based on the access network type. The wirelessdevice may initiate a NAS procedure by sending, to an access andmobility management function (AMF), a first NAS request message, whereinthe sending corresponds to a start of the first NAS period. The wirelessdevice may abort the NAS procedure in response to an in response to anexpiration of the first NAS period.

In an example, the first NAS period may be equal to a first value basedon the access network information indicating the NTN. In an example, thefirst NAS period may be equal to a second value based on the accessnetwork indicating the TN.

In an example, the access network information includes the first valueor the second value. In an example, the first value and/or the secondvalue is pre-configured in the wireless device. The second valuecorresponds to a shorter NAS period than the first value. The secondvalue may be shorter than the first value.

The NTN access network type is connected to the AMF and the TN accessnetwork type is connected to the AMF.

In an example, the wireless device may determine an operating mode ofthe wireless device based on the access network type. The wirelessdevice may determine the first NAS period based on the operating mode.In an example, the operating mode may comprise a terrestrial operationmode, a wide band terrestrial operation mode, a narrow band terrestrialoperation mode, a non-terrestrial operation mode, a non-terrestrial lowearth orbit (LEO) operation mode, a non-terrestrial medium earth orbit(MEP) operation mode, a non-terrestrial geostationary earth orbit (GEO)operation mode, a non-terrestrial unmanned aircraft system (UAS)operation mode, and/or the like.

In an example, the NTN (access network type) may comprise a low earthorbit (LEO) satellite type, a medium earth orbit (MET) satellite type, ageostationary earth orbit (GEO) satellite type, an unmanned aircraftsystem (UAS) platform type, a high elliptical orbit (HEO) platform type,and/or the like.

In an example, the TN (access network type) may comprise a narrow bandinternet of things types, an enhanced machine type communication (MTC)type, a wide-band evolved terrestrial radio access (WB-E-UTRA) type, anew radio (NR) type, and/or the like. In an example implementation, theTN (access network type) may comprise a wide-band evolved terrestrialradio access (WB-E-UTRA) type, a new radio (NR)type, and/or the like.

In an example, the wireless device may send a second NAS requestmessage, in response to the expiration of the first NAS period. Thesending of the second NAS request message may comprise a re-sending of acontent of the first NAS request message.

In an example, the wireless device may not send the second NAS requestmessage in response to receiving a first NAS response message prior tothe expiration of the first NAS period.

The first NAS response message may comprise backhaul network informationcorresponding to a core network. The backhaul network information maycomprise NTN type information, backhaul latency information, altitudeinformation and/or the like.

In an example, the wireless device may determine a second NAS periodbased on the first NAS period and the backhaul network information. Inan example, the wireless device may determine a second NAS period basedon the backhaul network information.

In an example, the second NAS period may be equal to the sum of firstNAS period and a delta value based on/in response to the backhaulnetwork information indicating the NTN. The second NAS period may beequal to the first NAS period based on the backhaul network informationindicating the TN.

The backhaul network information may include the delta value. In anexample, the delta value is pre-configured in the wireless device.

The wireless device may increment an NAS attempt counter by 1 inresponse to an expiration of the first NAS period.

The wireless device may not perform/initiate a NAS procedure in responseto the NAS attempt counter being equal a maximum retiral number.

In an example, a remote radio unit of the access network is an onboardto a satellite. The access network is an onboard to a satellite.

In an example, a wireless device may receive from an access network,access network information indicating an access network type of aplurality of access network types. The access network type may comprisea non-terrestrial network (NTN) access network type, a terrestrialnetwork (TN) access network type. The wireless device may determine afirst non-access stratum (NAS) timer value corresponding to a first NAStimer based on the access network type. The wireless device may initiatea NAS procedure by sending, to an access and mobility managementfunction (AMF), a first NAS request message. The wireless may start thefirst NAS timer corresponding to the NAS timer value in response toinitiating the NAS procedure. The wireless device may abort the NASprocedure, in response to an expiration of the first NAS timer.

In an example, a wireless device may determine, a first non-accessstratum (NAS) period as a default value. The wireless device may send toan access and mobility management function (AMF), a non-access stratum(NAS) request message requesting a registration of the wireless device.The wireless device may receive, from the AMF, a NAS response messageindicating a successful registration of the wireless device, wherein theNAS response message comprising a parameter. The wireless device mayre-determine the first NAS period based on the parameter. The parametermay comprise an index value indicating a sets of timer period, a timeoffset value, NAS retransmission timer setting info, and/or the like. Inan example, the default value is a preconfigured in the wireless device.In an example, the wireless device may receive the access network systeminformation comprising the default value.

In an example, a wireless device may send to an access and mobilitymanagement function (AMF), a first NAS request message, wherein thesending corresponds to a start of a NAS period. The wireless device mayreceive an NAS response message prior to an expiration of the NASperiod, wherein the NAS response message comprises backhaul networkinformation corresponding to a core network. The wireless device maydetermine a second non-access stratum (NAS) period based on the backhaulnetwork information. The wireless device may send to the AMF, a thirdNAS request message, wherein the sending corresponds to a start of thesecond NAS period. The wireless device may send a fourth NAS requestmessage in response to an expiration of the second NAS period.

In an example, a wireless device may send to an access and mobilitymanagement function (AMF), a first NAS request message, wherein thesending corresponds to a start of a NAS period. The wireless device mayreceive an NAS response message prior to an expiration of the NASperiod, wherein the NAS response message comprises backhaul networkinformation corresponding to a core network. The wireless device maydetermine a second non-access stratum (NAS) timer value corresponding tothe NAS timer based on the backhaul network information. The wirelessdevice may send to the AMF, a third NAS request message, wherein thesending corresponds to a start of the second NAS timer with the secondNAS timer value. The wireless device may send a fourth NAS requestmessage in response to an expiration of the second NAS timer.

In an example, the second NAS timer value is a first value based on thebackhaul network information indicating an NTN. The second NAS timervalue is a second value based on the backhaul network informationindicating a TN. The first value is larger than the first value.

Below some exemplary embodiments described above are summarized. It isemphasized, however, that the following enumeration, which includes 70items, is not an exhaustive but rather a summary of exemplary embodimentincluded in the above description.

According to various embodiments, a device such as, for example, awireless device, off-network wireless device, a base station, and/or thelike, may comprise one or more processors and memory. The memory maystore instructions that, when executed by the one or more processors,cause the device to perform a series of actions. Embodiments of exampleactions are illustrated in the accompanying figures and specification.Features from various embodiments may be combined to create yet furtherembodiments.

FIG. 32 is a flow diagram as per an aspect of an example embodiment ofthe present disclosure. At 3210, a wireless device may receive, from abase station, access network information indicating an access networktype of a plurality of access network types comprising: a geostationaryearth orbit (GEO) access network type; and a low earth orbit (LEO)access network type. At 3220, based on the access network type, thewireless device may select a first non-access stratum (NAS) period amonga plurality of NAS period. The plurality of NAS periods comprise: afirst value associated with the GEO access network type; and a secondvalue associated with the LEO access network type. At 3230, the wirelessdevice may initiate a NAS procedure by sending, to an access andmobility management function (AMF) via the base station, a first NASrequest message. A start of the first NAS period may be based on thesending. At 3240, the wireless device may abort the NAS procedure inresponse to an expiration of the first NAS period. According to variousembodiments, the base station may be a non-terrestrial network (NTN)base station.

According to various embodiments, the first value may be longer than thesecond value. According to various embodiments, the second value may befurther associated with a terrestrial network (TN) access network type.

According to various embodiments, the TN access network type maycomprise at least one of: a wide-band evolved terrestrial radio access(WB-E-UTRA) type; or a new radio (NR) type.

According to various embodiments, the wireless device may send to theAMF, a second NAS request message in response to the expiration of thefirst NAS period. The second NAS request message may be based on thefirst NAS request message.

According to various embodiments, the wireless device may receive fromthe AMF, a first NAS response message prior to the expiration of thefirst NAS period.

According to various embodiments, the wireless device may receive,backhaul network information corresponding to a core network. Thewireless device may determine a second NAS period based on the backhaulnetwork information. The wireless device may send to the AMF, a thirdNAS request message. A start of the second NAS period may be based onthe sending the third NAS request message.

According to various embodiments, the backhaul network informationcomprises at least one of: NTN type information; backhaul latencyinformation; or altitude information. According to various embodiments,the NTN type information comprises at least one of: a parameterindicating a GEO; a parameter indicating a medium earth orbit (MEO); ora parameter indicating a LEO.

According to various embodiments, a wireless device may send to anaccess and mobility management function (AMF) via a base station, afirst non-access stratum (NAS) request message. A start of a NAS periodmay be based on the sending. The wireless device may receive from theAMF, an NAS response message. The NAS response message may comprisebackhaul network information of a backhaul interface. The wirelessdevice may determine a second NAS period based on the backhaul networkinformation. The wireless device may send to the AMF, a third NASrequest message. A start of the second NAS period may be based on thesending the third NAS request message.

According to various embodiments, the backhaul interface may be betweenthe base station and the AMF. According to various embodiments, thereception of the NAS response message may be prior to an expiration ofthe NAS period.

According to various embodiments, the backhaul network information maycomprise at least one of: non-terrestrial network (NTN) typeinformation; backhaul latency information; or altitude information.

According to various embodiments, the NTN type information may compriseone of:

a geostationary earth orbit (GEO) NTN type; a medium earth orbit (MEO)NTN type; and a low earth orbit (LEO) NTN type.

According to various embodiments, the second NAS period is further basedon the first NAS period.

FIG. 33 is a flow diagram as per an aspect of an example embodiment ofthe present disclosure. At 3310, a wireless device may send to an accessand mobility management function (AMF) via a base station, a firstnon-access stratum (NAS) request message. The base station may beconnected to the AMF via a backhaul interface. At 3320, the wirelessdevice may receive from the AMF, an NAS response message. The NASresponse message may comprise information of the backhaul interface.

According to various embodiments, the information may comprise abackhaul interface type of a plurality of backhaul interface types. Theplurality of backhaul interface types may comprise a geostationary earthorbit (GEO) non-terrestrial network (NTN) type; a medium earth orbit(MEO) NTN type; and a low earth orbit (LEO) NTN type.

According to various embodiments, a wireless device may receive accessnetwork information from a base station. The access network informationmay indicate an access network type of a plurality of access networktypes. The plurality of access network types may comprise ageostationary earth orbit (GEO) access network type; and a low earthorbit (LEO) access network type. The wireless device may start a firstnon-access stratum (NAS) period based on sending, to an access andmobility management function (AMF) via the base station, a first NASrequest message to initiate a NAS procedure. The first NAS period may beone of a plurality of NAS periods comprising: a first value associatedwith the GEO access network type; and a second value associated with theLEO access network type. In response to an expiration of the first NASperiod, the wireless device may abort the NAS procedure.

According to various embodiments, a wireless device may receive accessnetwork information from a base station. The access network informationmay indicate an access network type of a plurality of access networktypes. The plurality of access network types may comprise ageostationary earth orbit (GEO) access network type; a low earth orbit(LEO) access network type; and a terrestrial network (TN) access networktype. The wireless device may start a first non-access stratum (NAS)period based on sending, to an access and mobility management function(AMF) via the base station, a first NAS request message to initiate aNAS procedure. The first NAS period may be one of a plurality of NASperiods comprising: a first value associated with the GEO access networktype; and a second value associated with the LEO access network type andthe TN access network type. In response to an expiration of the firstNAS period, the wireless device may abort the NAS procedure.

In this specification, a and an and similar phrases are to beinterpreted as at least one and one or more. In this specification, theterm may is to be interpreted as may, for example. In other words, theterm may is indicative that the phrase following the term may is anexample of one of a multitude of suitable possibilities that may, or maynot, be employed to one or more of the various embodiments. If A and Bare sets and every element of A is also an element of B, A is called asubset of B. In this specification, only non-empty sets and subsets areconsidered. For example, possible subsets of B={cell1, cell2} are:{cell1}, {cell2}, and {cell1, cell2}.

In this specification, parameters (Information elements: IEs) maycomprise one or more objects, and each of those objects may comprise oneor more other objects. For example, if parameter (IE) N comprisesparameter (IE) M, and parameter (IE) M comprises parameter (IE) K, andparameter (IE) K comprises parameter (information element) J, then, forexample, N comprises K, and N comprises J. In an example embodiment,when one or more messages comprise a plurality of parameters, it impliesthat a parameter in the plurality of parameters is in at least one ofthe one or more messages but does not have to be in each of the one ormore messages.

Many of the elements described in the disclosed embodiments may beimplemented as modules. A module is defined here as an isolatableelement that performs a defined function and has a defined interface toother elements. The modules described in this disclosure may beimplemented in hardware, software in combination with hardware,firmware, wetware (i.e. hardware with a biological element) or acombination thereof, which may be behaviorally equivalent. For example,modules may be implemented as a software routine written in a computerlanguage configured to be executed by a hardware machine (such as C,C++, Fortran, Java, Basic, Matlab or the like) or a modeling/simulationprogram such as Simulink, Stateflow, GNU Octave, or LabVIEWMathScript.Additionally, it may be possible to implement modules using physicalhardware that incorporates discrete or programmable analog, digitaland/or quantum hardware. Examples of programmable hardware comprise:computers, microcontrollers, microprocessors, application-specificintegrated circuits (ASICs); field programmable gate arrays (FPGAs); andcomplex programmable logic devices (CPLDs). Computers, microcontrollersand microprocessors are programmed using languages such as assembly, C,C++ or the like. FPGAs, ASICs and CPLDs are often programmed usinghardware description languages (HDL) such as VHSIC hardware descriptionlanguage (VHDL) or Verilog that configure connections between internalhardware modules with lesser functionality on a programmable device.Finally, it needs to be emphasized that the above mentioned technologiesare often employed in combination to achieve the result of a functionalmodule.

Example embodiments of the invention may be implemented using variousphysical and/or virtual network elements, software defined networking,virtual network functions.

The disclosure of this patent document incorporates material which issubject to copyright protection. The copyright owner has no objection tothe facsimile reproduction by anyone of the patent document or thepatent disclosure, as it appears in the Patent and Trademark Officepatent file or records, for the limited purposes required by law, butotherwise reserves all copyright rights whatsoever.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example, and notlimitation. It will be apparent to persons skilled in the relevantart(s) that various changes in form and detail can be made thereinwithout departing from the spirit and scope. In fact, after reading theabove description, it will be apparent to one skilled in the relevantart(s) how to implement alternative embodiments. Thus, the presentembodiments should not be limited by any of the above describedexemplary embodiments. In particular, it should be noted that, forexample purposes, the above explanation has focused on the example(s)using 5G AN. However, one skilled in the art will recognize thatembodiments of the invention may also be implemented in a systemcomprising one or more legacy systems or LTE. The disclosed methods andsystems may be implemented in wireless or wireline systems. The featuresof various embodiments presented in this invention may be combined. Oneor many features (method or system) of one embodiment may be implementedin other embodiments. A limited number of example combinations are shownto indicate to one skilled in the art the possibility of features thatmay be combined in various embodiments to create enhanced transmissionand reception systems and methods.

In addition, it should be understood that any figures which highlightthe functionality and advantages, are presented for example purposes.The disclosed architecture is sufficiently flexible and configurable,such that it may be utilized in ways other than that shown. For example,the actions listed in any flowchart may be re-ordered or optionally usedin some embodiments.

Further, the purpose of the Abstract of the Disclosure is to enable theU.S. Patent and Trademark Office and the public generally, andespecially the scientists, engineers and practitioners in the art whoare not familiar with patent or legal terms or phraseology, to determinequickly from a cursory inspection the nature and essence of thetechnical disclosure of the application. The Abstract of the Disclosureis not intended to be limiting as to the scope in any way.

Finally, it is the applicant's intent that only claims that include theexpress language means for or step for be interpreted under 35 U.S.C.112. Claims that do not expressly include the phrase means for or stepfor are not to be interpreted under 35 U.S.C. 112.

What is claimed is:
 1. A method comprising: receiving, by a wirelessdevice, access network information indicating an access network type;selecting, based on the access network type, a non-access stratum (NAS)period among: a first value associated with a geostationary earth orbit(GEO) non-terrestrial network (NTN) access network type; and a secondvalue associated with a terrestrial network (TN) access network type;sending, to an access and mobility management function (AMF), a NASrequest message; and starting, based on the sending, the NAS period. 2.The method of claim 1, wherein the receiving the access networkinformation comprises receiving the access network information from anon-terrestrial network (NTN) base station.
 3. The method of claim 2,wherein the sending the NAS request message comprises sending the NASrequest message to the AMF via the NTN base station.
 4. The method ofclaim 1, wherein the first value is longer than the second value.
 5. Themethod of claim 1, wherein the TN access network type comprises at leastone of: a wide-band evolved terrestrial radio access (WB-E-UTRA) type;or a new radio (NR) type.
 6. The method of claim 1, further comprisingsending, by the wireless device, a second NAS request message inresponse to expiration of the NAS period, wherein the second NAS requestmessage is based on the NAS request message.
 7. The method of claim 1,further comprising: receiving, by the wireless device from the AMF,backhaul network information corresponding to a core network;determining a second NAS period based on the backhaul networkinformation; and sending, to the AMF, a third NAS request message,wherein a start of the second NAS period is based on the sending thethird NAS request message.
 8. The method of claim 7, wherein thebackhaul network information comprises at least one of: NTN typeinformation; backhaul latency information; or altitude information. 9.The method of claim 8, wherein the NTN type information comprises atleast one of: a parameter indicating a GEO; a parameter indicating amedium earth orbit (MEO); or a parameter indicating a LEO.
 10. Awireless device, comprising: one or more processors; and memory storinginstructions that, when executed by the one or more processors, causethe wireless device to: receive access network information indicating anaccess network type; select, based on the access network type, anon-access stratum (NAS) period among: a first value associated with ageostationary earth orbit (GEO) non-terrestrial network (NTN) accessnetwork type; and a second value associated with a terrestrial network(TN) access network type; sending, to an access and mobility managementfunction (AMF), a NAS request message; and start, based on the sending,the NAS period.
 11. The wireless device of claim 10, wherein thereceiving the access network information comprises receiving the accessnetwork information from a non-terrestrial network (NTN) base station.12. The wireless device of claim 11, wherein the sending the NAS requestmessage comprises sending the NAS request message to the AMF via the NTNbase station.
 13. The wireless device of claim 10, wherein the firstvalue is longer than the second value.
 14. The wireless device of claim10, wherein the TN access network type comprises at least one of: awide-band evolved terrestrial radio access (WB-E-UTRA) type; or a newradio (NR) type.
 15. The wireless device of claim 10, wherein theinstructions, when executed by the one or more processors, further causethe wireless device to send a second NAS request message in response toexpiration of the NAS period, wherein the second NAS request message isbased on the NAS request message.
 16. The wireless device of claim 10,wherein the instructions, when executed by the one or more processors,further cause the wireless device to: receive, from the AMF, backhaulnetwork information corresponding to a core network; determine a secondNAS period based on the backhaul network information; and send, to theAMF, a third NAS request message, wherein a start of the second NASperiod is based on the sending the third NAS request message.
 17. Thewireless device of claim 16, wherein the backhaul network informationcomprises at least one of: NTN type information; backhaul latencyinformation; or altitude information.
 18. A system comprising: anon-terrestrial network (NTN) base station comprising: one or more firstprocessors; and first memory storing instructions that, when executed bythe one or more first processors, cause the NTN base station to transmitaccess network information indicating an access network type; and awireless device comprising: one or more second processors; and secondmemory storing instructions that, when executed by the one or moresecond processors, cause the wireless device to: receive the accessnetwork information; select, based on the access network type, anon-access stratum (NAS) period among: a first value associated with ageostationary earth orbit (GEO) non-terrestrial network (NTN) accessnetwork type; and a second value associated with a terrestrial network(TN) access network type; sending, to an access and mobility managementfunction (AMF), a NAS request message; and start, based on the sending,the NAS period.